WorldWideScience

Sample records for entire c-60 molecule

  1. Nanoelectromechanical switch operating by tunneling of an entire C-60 molecule

    DEFF Research Database (Denmark)

    Danilov, Andrey V.; Hedegård, Per; Golubev, Dimitrii S.

    2008-01-01

    (i) the relative contribution of tunneling, current induced heating and thermal fluctuations to the switching mechanism, (ii) the voltage dependent energy barrier (similar to 100-200 meV) separating the two states of the switch and (iii) the switching attempt frequency, omega(0) corresponding to a 2......We present a solid state single molecule electronic device where switching between two states with different conductance happens predominantly by tunneling of an entire C-60 molecule. This conclusion is based on a novel statistical analysis of similar to 10(5) switching events. The analysis yields...

  2. Controlled contact to a C-60 molecule

    DEFF Research Database (Denmark)

    Neel, N.; Kröger, J.; Limot, L.

    2007-01-01

    The tip of a low-temperature scanning tunneling microscope is approached towards a C-60 molecule adsorbed at a pentagon-hexagon bond on Cu(100) to form a tip-molecule contact. The conductance rapidly increases to approximate to 0.25 conductance quanta in the transition region from tunneling to co...

  3. Effective intermolecular potential and critical point for C60 molecule

    Science.gov (United States)

    Ramos, J. Eloy

    2017-07-01

    The approximate nonconformal (ANC) theory is applied to the C60 molecule. A new binary potential function is developed for C60, which has three parameters only and is obtained by averaging the site-site carbon interactions on the surface of two C60 molecules. It is shown that the C60 molecule follows, to a good approximation, the corresponding states principle with n-C8H18, n-C4F10 and n-C5F12. The critical point of C60 is estimated in two ways: first by applying the corresponding states principle under the framework of the ANC theory, and then by using previous computer simulations. The critical parameters obtained by applying the corresponding states principle, although very different from those reported in the literature, are consistent with the previous results of the ANC theory. It is shown that the Girifalco potential does not correspond to an average of the site-site carbon-carbon interaction.

  4. Hindered rotation of a copper phthalocyanine molecule on C60 : Experiments and molecular mechanics calculations

    NARCIS (Netherlands)

    Fendrich, M.; Wagner, Th.; Stöhr, M.; Möller, R.

    2006-01-01

    If copper phthalocyanine (CuPc) molecules are deposited on a Au(111) surface covered with a monolayer of C60, the molecules are found to adsorb individually onto the close-packed layer of C60. As the adsorption site of the CuPc is not symmetric with respect to the underlying C60 layer, the CuPc

  5. The nano-science of C60 molecule

    International Nuclear Information System (INIS)

    Rafii-Tabar, H.

    2002-01-01

    Over the past few years, nano-science and its associated nano-technology have emerged into prominence in research institutions across the world. They have brought about new scientific and engineering paradigms, allowing for the manipulation of single atoms and molecules, designing and fabricating new materials, atom-by-atom, and devices that operate on significantly reduced time and length scales. One important area of research in nano-science and nano technology is carbon-based physics in the form of fullerene physics. The C 6 0 molecule, and other cage-like fullerenes, together with carbon nano tubes provide objects that can be combined to generate three-dimensional functional structures for use in the anticipated nano-technology of future. The unique properties of C 6 0 can also be exploited in designing nano-phase thin films with applications in nano-scope device technology and processes such as nano-lithography. This requires a deep understanding of the highly complex process of adsorption of this molecule on a variety of substrates. We review the field of nano-scale nucleation and growth of C 6 0 molecules on some of the technologically important substrates. In addition to experimental results, the results of a set of highly accurate computational simulations are also reported

  6. Direct observation of hindered eccentric rotation of an individual molecule : Cu-phthalocyanine on C60

    NARCIS (Netherlands)

    Stöhr, Meike; Wagner, T; Gabriel, M; Weyers, B; Moller, R

    2002-01-01

    Individual Cu-phthalocyanine molecules have been investigated by scanning tunnel microscopy on a closed packed film of C-60 at various temperatures. The molecules are found to bind asymmetrically to one C-60. While they remain in one position at low temperature, they can hop between six equivalent

  7. STM study of C60F18 high dipole moment molecules on Au(111)

    Science.gov (United States)

    Bairagi, K.; Bellec, A.; Chumakov, R. G.; Menshikov, K. A.; Lagoute, J.; Chacon, C.; Girard, Y.; Rousset, S.; Repain, V.; Lebedev, A. M.; Sukhanov, L. P.; Svechnikov, N. Yu.; Stankevich, V. G.

    2015-11-01

    Scanning tunneling microscopy and spectroscopy studies of C60F18 molecules deposited on Au(111) are reported and compared to C60 molecules both at liquid helium temperature and room temperature (RT). Whereas adsorption and electronic properties of C60F18 single molecules were studied at low temperature (LT), self-assemblies were investigated at RT. In both cases, the fluorine atoms of the C60F18 molecules are pointed towards the surface. Individual C60F18 molecules on Au(111) have a HOMO-LUMO gap of 2.9 eV. The self-assembled islands exhibit a close-packed hexagonal lattice with amorphous borders. The comparison with C60 molecules clearly demonstrates the influence of the C60F18 electric dipole moment (EDM) on the electronic properties of single molecules and on the thermodynamics of self-assembled islands. Besides, the apparent height value of a separate molecule increases in a self-assembly environment as a result of a depolarization phenomenon.

  8. Formation of clusters composed of C60 molecules via self-assembly in critical fluids

    International Nuclear Information System (INIS)

    Fukuda, Takahiro; Ishii, Koji; Kurosu, Shunji; Whitby, Raymond; Maekawa, Toru

    2007-01-01

    Fullerenes are promising candidates for intelligent, functional nanomaterials because of their unique mechanical, electronic and chemical properties. However, it is necessary to invent some efficient but relatively simple methods of producing structures composed of fullerenes for the development of nanomechatronic, nanoelectronic and biochemical devices and sensors. In this paper, we show that various structures such as straight fibres, networks formed by fibres, wide sheets and helical structures, which are composed of C 60 molecules, are created by placing C 60 -crystals in critical ethane, carbon dioxide and xenon even though C 60 molecules do not dissolve or disperse in the above fluids. It is supposed, judging by the intermolecular potentials between C 60 and C 60 , between C 60 and ethane, and between ethane and ethane, that C 60 -clusters grow with the assistance of solvent molecules, which are trapped between C 60 molecules under critical conditions. This room-temperature self-assembly cluster growth process in critical fluids may open up a new methodology of forming structures built up with fullerenes without the need for any ultra-fine processing technologies

  9. Alignment of paired molecules of C60 within a hexagonal platform networked through hydrogen-bonds.

    Science.gov (United States)

    Hisaki, Ichiro; Nakagawa, Shoichi; Sato, Hiroyasu; Tohnai, Norimitsu

    2016-07-28

    We demonstrate, for the first time, that a hydrogen-bonded low-density organic framework can be applied as a platform to achieve periodic alignment of paired molecules of C60, which is the smallest example of a finite-numbered cluster of C60. The framework is a layered assembly of a hydrogen-bonded 2D hexagonal network (LA-H-HexNet) composed of dodecadehydrotribenzo[18]annulene derivatives.

  10. Hydrogen molecules inside fullerene C70: quantum dynamics, energetics, maximum occupancy, and comparison with C60.

    Science.gov (United States)

    Sebastianelli, Francesco; Xu, Minzhong; Bacić, Zlatko; Lawler, Ronald; Turro, Nicholas J

    2010-07-21

    Recent synthesis of the endohedral complexes of C(70) and its open-cage derivative with one and two H(2) molecules has opened the path for experimental and theoretical investigations of the unique dynamic, spectroscopic, and other properties of systems with multiple hydrogen molecules confined inside a nanoscale cavity. Here we report a rigorous theoretical study of the dynamics of the coupled translational and rotational motions of H(2) molecules in C(70) and C(60), which are highly quantum mechanical. Diffusion Monte Carlo (DMC) calculations were performed for up to three para-H(2) (p-H(2)) molecules encapsulated in C(70) and for one and two p-H(2) molecules inside C(60). These calculations provide a quantitative description of the ground-state properties, energetics, and the translation-rotation (T-R) zero-point energies (ZPEs) of the nanoconfined p-H(2) molecules and of the spatial distribution of two p-H(2) molecules in the cavity of C(70). The energy of the global minimum on the intermolecular potential energy surface (PES) is negative for one and two H(2) molecules in C(70) but has a high positive value when the third H(2) is added, implying that at most two H(2) molecules can be stabilized inside C(70). By the same criterion, in the case of C(60), only the endohedral complex with one H(2) molecule is energetically stable. Our results are consistent with the fact that recently both (H(2))(n)@C(70) (n = 1, 2) and H(2)@C(60) were prepared, but not (H(2))(3)@C(70) or (H(2))(2)@C(60). The ZPE of the coupled T-R motions, from the DMC calculations, grows rapidly with the number of caged p-H(2) molecules and is a significant fraction of the well depth of the intermolecular PES, 11% in the case of p-H(2)@C(70) and 52% for (p-H(2))(2)@C(70). Consequently, the T-R ZPE represents a major component of the energetics of the encapsulated H(2) molecules. The inclusion of the ZPE nearly doubles the energy by which (p-H(2))(3)@C(70) is destabilized and increases by 66% the

  11. Nanoscale control of reversible chemical reaction between fullerene C60 molecules using scanning tunneling microscope.

    Science.gov (United States)

    Nakaya, Masato; Kuwahara, Yuji; Aono, Masakazu; Nakayama, Tomonobu

    2011-04-01

    The nanoscale control of reversible chemical reactions, the polymerization and depolymerization between C60 molecules, has been investigated. Using a scanning tunneling microscope (STM), the polymerization and depolymerization can be controlled at designated positions in ultrathin films of C60 molecules. One of the two chemical reactions can be selectively induced by controlling the sample bias voltage (V(s)); the application of negative and positive values of V(s) results in polymerization and depolymerization, respectively. The selectivity between the two chemical reactions becomes extremely high when the thickness of the C60 film increases to more than three molecular layers. We conclude that STM-induced negative and positive electrostatic ionization are responsible for the control of the polymerization and depolymerization, respectively.

  12. Precise Orientation of a Single C60 Molecule on the Tip of a Scanning Probe Microscope

    Science.gov (United States)

    Chiutu, C.; Sweetman, A. M.; Lakin, A. J.; Stannard, A.; Jarvis, S.; Kantorovich, L.; Dunn, J. L.; Moriarty, P.

    2012-06-01

    We show that the precise orientation of a C60 molecule which terminates the tip of a scanning probe microscope can be determined with atomic precision from submolecular contrast images of the fullerene cage. A comparison of experimental scanning tunneling microscopy data with images simulated using computationally inexpensive Hückel theory provides a robust method of identifying molecular rotation and tilt at the end of the probe microscope tip. Noncontact atomic force microscopy resolves the atoms of the C60 cage closest to the surface for a range of molecular orientations at tip-sample separations where the molecule-substrate interaction potential is weakly attractive. Measurements of the C60C60 pair potential acquired using a fullerene-terminated tip are in excellent agreement with theoretical predictions based on a pairwise summation of the van der Waals interactions between C atoms in each cage, i.e., the Girifalco potential [L. Girifalco, J. Phys. Chem. 95, 5370 (1991)JPCHAX0022-365410.1021/j100167a002].

  13. Interaction of multicharged ions with molecules (CO2, C60) by coincident electron spectroscopy

    International Nuclear Information System (INIS)

    Moretto-Capelle, P.; Bordenave-Montesquieu, D.; Bordenave-Montesquieu, A.

    2001-01-01

    First results for the investigation of electron capture processes in collisions between multicharged ions and molecule targets using electron spectroscopy in coincidence with charged fragments, are presented. It is shown that a much more detailed investigation of the capture reaction can be achieved using molecular instead of heavy atomic targets provided that an analysis of the target dissociation is made. The collisional systems 18 O 8+ +Ar, CO 2 and C 60 have been studied at 80 keV. Non coincident electron spectra as well as first results of double or triple coincidence experiments are discussed. Kinetic energy distributions of the C n + fragments (n=1 to 8) produced in multiple capture processes from C 60 target are given. A detailed investigation of the double capture process with CO 2 molecule allows the measurement of kinetic energy release distributions (KERD) which characterize the dissociation of CO 2 2+ molecular ions; our results are found to be very similar to those measured in double photoionisation experiments. (orig.)

  14. Self-interaction corrections applied to Mg-porphyrin, C60, and pentacene molecules

    International Nuclear Information System (INIS)

    Pederson, Mark R.; Baruah, Tunna; Basurto, Luis; Kao, Der-you

    2016-01-01

    We have applied a recently developed method to incorporate the self-interaction correction through Fermi orbitals to Mg-porphyrin, C 60 , and pentacene molecules. The Fermi-Löwdin orbitals are localized and unitarily invariant to the Kohn-Sham orbitals from which they are constructed. The self-interaction-corrected energy is obtained variationally leading to an optimum set of Fermi-Löwdin orbitals (orthonormalized Fermi orbitals) that gives the minimum energy. A Fermi orbital, by definition, is dependent on a certain point which is referred to as the descriptor position. The degree to which the initial choice of descriptor positions influences the variational approach to the minimum and the complexity of the energy landscape as a function of Fermi-orbital descriptors is examined in detail for Mg-porphyrin. The applications presented here also demonstrate that the method can be applied to larger molecular systems containing a few hundred electrons. The atomization energy of the C 60 molecule within the Fermi-Löwdin-orbital self-interaction-correction approach is significantly improved compared to local density approximation in the Perdew-Wang 92 functional and generalized gradient approximation of Perdew-Burke-Ernzerhof functionals. The eigenvalues of the highest occupied molecular orbitals show qualitative improvement.

  15. Calculations on the Nonlinear Second—Order Optical Polarizabilities for Series of Donor—C60 Molecules

    Institute of Scientific and Technical Information of China (English)

    刘孝娟; 封继康; 任爱民

    2003-01-01

    The equilibrium geometries and UV-visible spectra of a series of donor-C60 molecules were obtained by means of the AM1 and INDO/CI method,on the basis of accurate geometric and electronic structures.The nonlinear second-order optical polarizabilities were calculated using the method INDO/SDCI combined with the Sum-Over-States(SOS) expression.The calculatedβ(λ=1.34μm) values are 28.81,48.56,57.33,66.99,70.85,85.84,and 142.14(×10-30 esu) for the molecules A,B,C,D,E,F and G,respectively.The frontier orbitals were plot for the representative molecules in order to exhibit the intramolecular charge transfer.The results indicate the introduction of thienylethylene can enhance the NLO response and the dimethylaniline-substituted dithienyl-ethylene-C60 (molecule G) possesses the largest NLO second-order optical polarizability.The large β values can be attributed to the charge transfer between the substituents and C60,as well as within the three-dimensional conjugated sphere of C60.

  16. Bioapplication and activity of fullerenol C60(OH)24

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-29

    Dec 29, 2008 ... represent a class of sphere-shaped molecules made entirely of .... 4942 Afr. J. Biotechnol. fullerenes. ... C60 and fullerenols C60(OH)x apparently employ different ... Alzheimer's and Parkinson's diseases, type-C hepatitis.

  17. Electrical bistabilities and memory stabilities of nonvolatile bistable devices fabricated utilizing C60 molecules embedded in a polymethyl methacrylate layer

    International Nuclear Information System (INIS)

    Cho, Sung Hwan; Lee, Dong Ik; Jung, Jae Hun; Kim, Tae Whan

    2009-01-01

    Current-voltage (I-V) measurements on Al/fullerene (C 60 ) molecules embedded in polymethyl methacrylate/Al devices at 300 K showed a current bistability due to the existence of the C 60 molecules. The on/off ratio of the current bistability for the memory devices was as large as 10 3 . The retention time of the devices was above 2.5 x 10 4 s at room temperature, and cycling endurance tests on these devices indicated that the ON and OFF currents showed no degradation until 50 000 cycles. Carrier transport mechanisms for the nonvolatile bistable devices are described on the basis of the I-V experimental and fitting results.

  18. Ion collision-induced chemistry in pure and mixed loosely bound clusters of coronene and C60 molecules.

    Science.gov (United States)

    Domaracka, Alicja; Delaunay, Rudy; Mika, Arkadiusz; Gatchell, Michael; Zettergren, Henning; Cederquist, Henrik; Rousseau, Patrick; Huber, Bernd A

    2018-05-23

    Ionization, fragmentation and molecular growth have been studied in collisions of 22.5 keV He2+- or 3 keV Ar+-projectiles with pure loosely bound clusters of coronene (C24H12) molecules or with loosely bound mixed C60-C24H12 clusters by using mass spectrometry. The heavier and slower Ar+ projectiles induce prompt knockout-fragmentation - C- and/or H-losses - from individual molecules and highly efficient secondary molecular growth reactions before the clusters disintegrate on picosecond timescales. The lighter and faster He2+ projectiles have a higher charge and the main reactions are then ionization by ions that are not penetrating the clusters. This leads mostly to cluster fragmentation without molecular growth. However, here penetrating collisions may also lead to molecular growth but to a much smaller extent than with 3 keV Ar+. Here we present fragmentation and molecular growth mass distributions with 1 mass unit resolution, which reveals that the same numbers of C- and H-atoms often participate in the formation and breaking of covalent bonds inside the clusters. We find that masses close to those with integer numbers of intact coronene molecules, or with integer numbers of both intact coronene and C60 molecules, are formed where often one or several H-atoms are missing or have been added on. We also find that super-hydrogenated coronene is formed inside the clusters.

  19. Quick synthesis of highly aligned or randomly oriented nanofibrous structures composed of C60 molecules via self-assembly

    International Nuclear Information System (INIS)

    Kurosu, Shunji; Fukuda, Takahiro; Maekawa, Toru

    2013-01-01

    Assemblies, which are composed of nanoparticles such as nanofibres, have been intensively studied in recent years. This has particularly been the case in the field of biomedicine, where the aim is to develop efficient methodologies for capturing and separating target biomolecules and cells and/or encouraging bio-chemical reactions, utilizing the extremely high surface area to volume ratio of assemblies. There is an urgent need for the development of a quick synthesis method of forming nanofibrous structures on the surface of biomedical microchips and devices for the investigation of the interactions between biomolecules/cells and the nanostructures. Here, we produce nanofibrous structures composed of C 60 molecules, which are aligned in one direction or randomly oriented, by dissolving C 60 molecules and sulphur in benzene and evaporating a droplet of the solution on a glass substrate under appropriate conditions. The synthesis time is as short as 30 s. Sulphur is extracted and nanofibres are crystallized by leaving them in supercritical carbon dioxide. (paper)

  20. Implanting very low energy atomic ions into surface adsorbed cage molecules: the formation/emission of Cs/C60+

    International Nuclear Information System (INIS)

    Kolodney, Eli; Kaplan, Andrey; Manor, Yoni; Bekkerman, Anatoly; Tsipinyuk, Boris

    2004-01-01

    Full Text: We demonstrate the formation of an endo-complex via a collision of energetic ions with molecular overlayers on a surface. An incoming atomic ion is encapsulated inside a very large molecule or cluster by implanting the primary ion into the target species, which then recovers its original structure or rearrange itself around the implanted ion in some stable configuration. Here we describe an experiment resulting in the formation and ejection of an endo-complex, within a single collision. We study the formation and emission of endohedral fullerenes, Cs/C 60 + and Cs/C 70 + , following a single collision of Cs + ion with a sub-monolayer of C 60 (steady state coverage) on gold and silicon surfaces and with a sub-monolayer of C 70 on gold. A continuous low energy (E 0 =35-220 eV) Cs + ion beam hit the Cs + covered surface and the collisional formation and ejection of the endohedral Cs/Cs 60 + complex, within a single Cs + /C 60 collision was observed and characterized. Several experimental observations clearly demonstrate the single collision nature of the combined atom penetration endo-complex ejection event. The fullerene molecule is actually being picked up off the surface by the penetrating Cs + ion. The evidence for the trapping of the Cs + ion inside the fullerene cage is given both by the appearance of the Cs/Cs (602-2n) + (n=1-5) sequence and its termination at Cs/Cs 50 + . Kinetic Energy Distributions (KEDs) of the outgoing Cs/Cs 60 + were measured for two different Cs + impact energies under field-free conditions. The most striking observation is the near independence of the KEDs on the impact energy. Both KEDs peak around 1.2 eV with similar line shapes. A simple model for the formation/ejection/fragmentation dynamics of the endohedral complex is proposed and is found to be in good agreement with the experimental results

  1. Porous polymer monoliths functionalized through copolymerization of a C60 fullerene-containing methacrylate monomer for highly efficient separations of small molecules

    KAUST Repository

    Chambers, Stuart D.; Holcombe, Thomas W.; Švec, František; Frechet, Jean

    2011-01-01

    been prepared and their chromatographic performance have been tested for the separation of small molecules in the reversed phase. While addition of the C60-fullerene monomer to the glycidyl methacrylate-based monolith enhanced column efficiency 18-fold

  2. Evaluation of the Electronic Structure of Single-Molecule Junctions Based on Current-Voltage and Thermopower Measurements: Application to C60 Single-Molecule Junction.

    Science.gov (United States)

    Komoto, Yuki; Isshiki, Yuji; Fujii, Shintaro; Nishino, Tomoaki; Kiguchi, Manabu

    2017-02-16

    The electronic structure of molecular junctions has a significant impact on their transport properties. Despite the decisive role of the electronic structure, a complete characterization of the electronic structure remains a challenge. This is because there is no straightforward way of measuring electron spectroscopy for an individual molecule trapped in a nanoscale gap between two metal electrodes. Herein, a comprehensive approach to obtain a detailed description of the electronic structure in single-molecule junctions based on the analysis of current-voltage (I-V) and thermoelectric characteristics is described. It is shown that the electronic structure of the prototypical C 60 single-molecule junction can be resolved by analyzing complementary results of the I-V and thermoelectric measurement. This combined approach confirmed that the C 60 single-molecule junction was highly conductive with molecular electronic conductances of 0.033 and 0.003 G 0 and a molecular Seebeck coefficient of -12 μV K -1 . In addition, we revealed that charge transport was mediated by a LUMO whose energy level was located 0.5≈0.6 eV above the Fermi level of the Au electrode. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. The T1u x 8 hg Jahn-Teller system - an improved model for the C60-molecule

    International Nuclear Information System (INIS)

    Rough, S.M.; Dunn, J.L.; Bates, C.A.

    1997-01-01

    The ground state of C 60 - gives rise to a T 1u x 8 h g Jahn-Teller (JT) system. A proof is presented showing that the presence of eight active h g modes rather than one makes little difference to the mathematical complexity of this problem compared to the simpler single-mode variant. After showing that the T 1u x 8 h g Jahn-Teller system has the same electronic eigenstates as the T 1u x h g Jahn-Teller system, the inversion splitting and first-order reduction factors are derived. (orig.)

  4. Packing C60 in Boron Nitride Nanotubes

    Science.gov (United States)

    Mickelson, W.; Aloni, S.; Han, Wei-Qiang; Cumings, John; Zettl, A.

    2003-04-01

    We have created insulated C60 nanowire by packing C60 molecules into the interior of insulating boron nitride nanotubes (BNNTs). For small-diameter BNNTs, the wire consists of a linear chain of C60 molecules. With increasing BNNT inner diameter, unusual C60 stacking configurations are obtained (including helical, hollow core, and incommensurate) that are unknown for bulk or thin-film forms of C60. C60 in BNNTs thus presents a model system for studying the properties of dimensionally constrained ``silo'' crystal structures. For the linear-chain case, we have fused the C60 molecules to form a single-walled carbon nanotube inside the insulating BNNT.

  5. DFT calculations of the charged states of N@C60 and Fe4 single molecule magnets investigated in tunneling spectroscopy

    Science.gov (United States)

    Nossa, Javier; Islam, Fhokrul; Canali, Carlo; Pederson, Mark

    2012-02-01

    For device applications of single molecule magnets (SMMs) in high-density information storage and quantum-state control it is essential that the magnetic properties of the molecules remain stable under the influence of metallic contacts or surface environment. Recent tunneling experiments [1, 2] on N@C60 and Fe4 SMM have shown that these molecules preserve their magnetic characteristics when they are used as the central island of single-electron transistors. Although quantum spin models have been used extensively to study theoretically tunneling spectroscopy of SMMs, it has been shown recently that the orbital degrees of freedom, which is absent in spin models, can significantly affect the tunneling conductance [3]. In this work we present first-principles calculations of the neutral and charged states of N@C60 and Fe4 SMMs, and discuss a strategy to include their properties into a theory of quantum transport. We also present results of the magnetic anisotropy for the different charge states of Fe4 and discuss their relevance for experiments [2] in the sequential tunneling and cotunnelling regimes. [4pt] [1]. N. Roch et al., Phys. Rev. B 83, 081407 (2011). [0pt] [2]. A.S. Zyazin et al., Nano Lett. 10, 3307 (2010). [0pt] [3]. L. Michalak et al., Phys. Rev. Lett. 104, 017202 (2010).

  6. Effects of inter-fullerene π-band mixings in the photoexcitation of hybrid plasmons in the C60@C240 molecule

    Science.gov (United States)

    de, Rume; Madjet, Mohamed; Chakraborty, Himadri

    2013-05-01

    We perform a detailed study of the ground state electronic structure of a two-layer fullerene onion molecule C60@C240. Calculations are carried out in a quantum mechanical framework of local density approximation (LDA) where the onion's ion-core of sixty C4+ ions from C60 and two hundred and forty of those from C240 is smeared into a classical jellium distribution. Significant inter-fullerene mixing between the bands of single-node radial symmetry, the π-bands, is found. We then compute the photoionization from all the levels of the system using a time-dependent version of LDA at photon energies where the ionization is dominated by the inter-layer hybridization of collective plasmon resonances. It is determined, by comparing the isolated fullerene cross sections with the cross section of the onion system for both π and σ (having nodeless radial waves) symmetry, that the π-band mixing is predominantly responsible for the production of plasmon hybrids. Supported by NSF and DOE.

  7. Novel Crystal Structure C60 Nanowire

    Science.gov (United States)

    Mickelson, William; Aloni, Shaul; Han, Weiqiang; Cumings, John; Zettl, Alex

    2003-03-01

    We have created insulated C60 nanowire by packing C60 molecules into the interior of insulating boron nitride (BN) nanotubes. For small-diameter BN tubes, the wire consists of a linear chain of C60's. With increasing BN tube inner diameter, novel C60 stacking configurations are obtained (including helical, hollow core, and incommensurate) which are unknown for bulk or thin film forms of C60. C60 in BN nanotubes presents a model system for studying the properties of new dimensionally-constrained "silo" crystal structures.

  8. Porous polymer monoliths functionalized through copolymerization of a C60 fullerene-containing methacrylate monomer for highly efficient separations of small molecules

    KAUST Repository

    Chambers, Stuart D.

    2011-12-15

    Monolithic poly(glycidyl methacrylate-co-ethylene dimethacrylate) and poly(butyl methacrylate-co-ethylene dimethacrylate) capillary columns, which incorporate the new monomer [6,6]-phenyl-C 61-butyric acid 2-hydroxyethyl methacrylate ester, have been prepared and their chromatographic performance have been tested for the separation of small molecules in the reversed phase. While addition of the C60-fullerene monomer to the glycidyl methacrylate-based monolith enhanced column efficiency 18-fold, to 85 000 plates/m at a linear velocity of 0.46 mm/s and a retention factor of 2.6, when compared to the parent monolith, the use of butyl methacrylate together with the carbon nanostructured monomer afforded monolithic columns with an efficiency for benzene exceeding 110 000 plates/m at a linear velocity of 0.32 mm/s and a retention factor of 4.2. This high efficiency is unprecedented for separations using porous polymer monoliths operating in an isocratic mode. Optimization of the chromatographic parameters affords near baseline separation of 6 alkylbenzenes in 3 min with an efficiency of 64 000 plates/m. The presence of 1 wt % or more of water in the polymerization mixture has a large effect on both the formation and reproducibility of the monoliths. Other factors such as nitrogen exposure, polymerization conditions, capillary filling method, and sonication parameters were all found to be important in producing highly efficient and reproducible monoliths. © 2011 American Chemical Society.

  9. Kinetic energies of charged fragments resulting from multifragmentation and asymmetric fission of the C60 molecule in collisions with monocharged ions (2-130 keV)

    International Nuclear Information System (INIS)

    Rentenier, A; Bordenave-Montesquieu, D; Moretto-Capelle, P; Bordenave-Montesquieu, A

    2003-01-01

    Multifragmentation and asymmetric fission (AF) of the C 60 molecule induced by H + , H 2 + , H 3 + and He + ions at medium collision energies (2-130 keV) are considered. Momenta and kinetic energies of C n + fragment ions (n = 1- 12) are deduced from an analysis of time-of-flight spectra. In multifragmentation processes, momenta are found to be approximately constant when n > 2, a behaviour which explains that the most probable kinetic energy, as well as the width of the kinetic energy distributions, is found to be inversely proportional to the fragment size n; both momenta and kinetic energies are independent of the velocity and nature of the projectile, and hence of the energy deposit. A specific study of the AF shows that the kinetic energies of C 2 + , C 4 + and C 6 + fragments are also independent of the collision velocity and projectile species; a quantitative agreement is found with values deduced from kinetic energy release measurements by another group in electron impact experiments, and the observed decrease when the mass of the light fragment increases is also reproduced. A quantitative comparison of AF and multifragmentation for the n = 2, 4 and 6 fragment ions shows that kinetic energies in AF exceed that in multifragmentation, a result which explains the oscillations observed when momenta or kinetic energies of fragments are plotted against the n-value. The AF yield is also found to scale with the energy deposit in the collision velocity range extending below the velocity at the maximum of the electronic stopping power; except for protons, it remains negligible with respect to multifragmentation as soon as the total energy deposit exceeds about 100 eV

  10. STM topographical images of C60

    International Nuclear Information System (INIS)

    Wang, Z.; Zhang, P.; Moskovits, M.

    1991-01-01

    In this paper STM topographical images of C 60 are reported. The images are consistent with a molecule approximately 9 Angstrom in diameter possessing the now-famous soccer ball structure. With the molecule deposited on gold, its atomic structure is not resolved. On graphite the structure of the within the borders of the C 60 molecule is dominated by that of the graphite forming a moire-like pattern. Some evidence of atomic structure is seen in multilayers of C 60 where some five- and six-membered rings are visible. These may, however, be features of fragments of the fullerene rather than whole molecules

  11. An ab initio study of the field-induced position change of a C60 molecule adsorbed on a gold tip

    DEFF Research Database (Denmark)

    Stadler, Robert; Kubatkin, S.; Bjørnholm, Thomas

    2007-01-01

    lightning rod effect which might explain the switching between configurations found in experiments. We also analyse our results for the adsorption energetics in terms of an electrostatic expression for the total energy, where the dependence of the polarizability of the junction on the position of the C60...

  12. Electronic structure of single crystal C60

    International Nuclear Information System (INIS)

    Wu, J.; Shen, Z.X.; Dessau, D.S.; Cao, R.; Marshall, D.S.; Pianetta, P.; Lindau, I.; Yang, X.; Terry, J.; King, D.M.; Wells, B.O.; Elloway, D.; Wendt, H.R.; Brown, C.A.; Hunziker, H.; Vries, M.S. de

    1992-01-01

    We report angle-resolved photoemission data from single crystals of C 60 cleaved in UHV. Unlike the other forms of pure carbon, the valence band spectrum of C 60 consists of many sharp features that can be essentially accounted for by the quantum chemical calculations describing individual molecules. This suggests that the electronic structure of solid C 60 is mainly determined by the bonding interactions within the individual molecules. We also observe remarkable intensity modulations of the photoemission features as a function of photon energy, suggesting strong final state effects. Finally, we address the issue of the band width of the HOMO state of C 60 . We assert that the width of the photoemission peak of C 60 does not reflect the intrinsic band width because it is broadened by the non 0-0 transitions via the Franck-Condon principle. Our view point provides a possible reconciliation between these photoemission data and those measured by other techniques. (orig.)

  13. Highly Stable [C60AuC60]+/- Dumbbells.

    Science.gov (United States)

    Goulart, Marcelo; Kuhn, Martin; Martini, Paul; Chen, Lei; Hagelberg, Frank; Kaiser, Alexander; Scheier, Paul; Ellis, Andrew M

    2018-05-17

    Ionic complexes between gold and C 60 have been observed for the first time. Cations and anions of the type [Au(C 60 ) 2 ] +/- are shown to have particular stability. Calculations suggest that these ions adopt a C 60 -Au-C 60 sandwich-like (dumbbell) structure, which is reminiscent of [XAuX] +/- ions previously observed for much smaller ligands. The [Au(C 60 ) 2 ] +/- ions can be regarded as Au(I) complexes, regardless of whether the net charge is positive or negative, but in both cases, the charge transfer between the Au and C 60 is incomplete, most likely because of a covalent contribution to the Au-C 60 binding. The C 60 -Au-C 60 dumbbell structure represents a new architecture in fullerene chemistry that might be replicable in synthetic nanostructures.

  14. Fragmentation of the C60 molecule in collision with light ions studied by a multi-correlation technique. Cross-sections, electron spectroscopy

    International Nuclear Information System (INIS)

    Rentenier, A.

    2004-04-01

    A quantitative study of the C60 fullerenes fragmentation in collision with light ions (H n + with n=1,2,3, He q+ with q=1,2) in the velocity range 0,1 - 2,3 u.a.) is presented. The multi-correlation technique, developed between fragment ions and electrons with well defined energy, has enlightened some of the dependences and properties of fragmentation mechanisms (cross sections, electron spectroscopy, size distributions, kinetic energy of fragment ions, Campi's scatter plot, activation energies). The deposited energy hence appeared as an important parameter. Cross sections have been measured, for the first time, for all the collisional processes. Ionisation and capture only depends on the collision velocity. On the other hand, scaling laws with the deposited energy have been observed for the cross sections of multifragmentation, which depends on the collision energy and the nature of the projectile. The deposited energy has also been found as an essential parameter to understand the evolution of the charged fragment size distributions. The electron spectroscopy, achieved at an emission angle of 35 degrees, showed spectra peaked at important energies (from 5 to 20 eV). The spectra shape depends on the collision velocity. A first theoretical analysis points out the link between the observed energy distribution and the presence of a centrifugal potential barrier. Finally, correlation experiments between produced ions and electron energy reveal that electron energy increases with internal energy. (author)

  15. π plasmon modes in C60 clusters

    International Nuclear Information System (INIS)

    Nguyen Van Giai; Lipparini, E.

    1992-07-01

    RPA correlations and collective excitations of π electrons in the C 60 cluster, the fullerene molecule are studied, by using the sum rule approach and linear response theory. The results for the excitation spectrum are discussed in relation to experimental data and to other theoretical approaches. (K.A.) 17 refs.; 4 figs

  16. Fragmentation of the C60 molecule in collision with light ions studied by a multi-correlation technique. Cross-sections, electron spectroscopy; Fragmentation de la molecule C60 par impact d'ions legers etudiee en multicorrelation. Sections efficaces, spectroscopie d'electrons

    Energy Technology Data Exchange (ETDEWEB)

    Rentenier, A

    2004-04-01

    A quantitative study of the C60 fullerenes fragmentation in collision with light ions (H{sub n}{sup +} with n=1,2,3, He{sup q+} with q=1,2) in the velocity range 0,1 - 2,3 u.a.) is presented. The multi-correlation technique, developed between fragment ions and electrons with well defined energy, has enlightened some of the dependences and properties of fragmentation mechanisms (cross sections, electron spectroscopy, size distributions, kinetic energy of fragment ions, Campi's scatter plot, activation energies). The deposited energy hence appeared as an important parameter. Cross sections have been measured, for the first time, for all the collisional processes. Ionisation and capture only depends on the collision velocity. On the other hand, scaling laws with the deposited energy have been observed for the cross sections of multifragmentation, which depends on the collision energy and the nature of the projectile. The deposited energy has also been found as an essential parameter to understand the evolution of the charged fragment size distributions. The electron spectroscopy, achieved at an emission angle of 35 degrees, showed spectra peaked at important energies (from 5 to 20 eV). The spectra shape depends on the collision velocity. A first theoretical analysis points out the link between the observed energy distribution and the presence of a centrifugal potential barrier. Finally, correlation experiments between produced ions and electron energy reveal that electron energy increases with internal energy. (author)

  17. Diffraction symmetry in crystalline, close-packed C60

    International Nuclear Information System (INIS)

    Fleming, R.M.; Siegrist, T.; Marsh, P.M.; Hessen, B.; Kortan, A.R.; Murphy, D.W.; Haddon, R.C.; Tycko, R.; Dabbagh, G.; Mujsce, A.M.

    1991-01-01

    The authors have grown crystals of the carbon structure C 60 by sublimation. In contrast to solution-grown crystals, the sublimed crystals have long range order with no evidence of solvent inclusions. Sublimed C 60 forms three dimensional, faceted crystals with a close-packed, face centered cubic unit cell. The authors have refined a crystal structure using the soccer ball model of the C 60 molecule. The results from this paper indicate that the C 60 molecule has the expected spherical shape, however the data are not sufficiently accurate to unambiguously determine atomic positions

  18. Structure of C60: Partial orientational order in the room-temperature modification of C60

    International Nuclear Information System (INIS)

    Buergi, H.B.; Restori, R.; Schwarzenbach, D.

    1993-01-01

    Using published synchrotron X-ray data, the room-temperature scattering density distribution of pure C 60 has been parametrized in terms of a combination of eight oriented symmetry-related images of the molecule, and of a freely spinning molecule. Corresponding populations are 61 and 39%. The oriented part of the model is obtained, in good approximation, by imposing m anti 3m symmetry on the energetically more favourable major orientation in the low-temperature structure of C 60 . The model was refined using angle restraints to impose the icosahedral molecular symmetry and displacement-factor restraints to restrict thermal movements to rigid-body translations and librations. Translational displacement factors are in the range 0.017-0.023 A 2 . The orientational probability density distribution obtained from the model shows maxima for C 60 orientations possessing anti 3m crystallographic site symmetry. It is also relatively large for the C 60 orientations with cubic site symmetry m anti 3. The smallest energy barrier for reorientation between different anti 3m orientations via an m anti 3 orientation appears to be less than 2 kJ mol -1 . On average, 75% of the intermolecular contacts of the oriented molecules are longer than those observed in the low-temperature structure, the other 25% are less favourable. The second orientation of C 60 found in the low-temperature structure could not be identified at room temperature. (orig.)

  19. Nanocomposite Materials of Alternately Stacked C60 Monolayer and Graphene

    Directory of Open Access Journals (Sweden)

    Makoto Ishikawa

    2010-01-01

    Full Text Available We synthesized the novel nanocomposite consisting alternately of a stacked single graphene sheet and a C60 monolayer by using the graphite intercalation technique in which alkylamine molecules help intercalate large C60 molecules into the graphite. Moreover, it is found that the intercalated C60 molecules can rotate in between single graphene sheets by using C13 NMR measurements. This preparation method provides a general way for intercalating huge fullerene molecules into graphite, which will lead to promising materials with novel mechanical, physical, and electrical properties.

  20. Nanocomposite Materials of Alternately Stacked C60 Monolayer and Graphene

    International Nuclear Information System (INIS)

    Ishikawa, M.; Miura, K.; Kamiya, S.; Yoshimoto, S.; Suzuki, M.; Kuwahara, D.; Sasaki, N.

    2010-01-01

    We synthesized the novel nanocomposite consisting alternately of a stacked single graphene sheet and a C 60 monolayer by using the graphite intercalation technique in which alkylamine molecules help intercalate large C 60 molecules into the graphite. Moreover, it is found that the intercalated C 60 molecules can rotate in between single graphene sheets by using C 13 NMR measurements. This preparation method provides a general way for intercalating huge fullerene molecules into graphite, which will lead to promising materials with novel mechanical, physical, and electrical properties.

  1. Material properties and purity of C60

    International Nuclear Information System (INIS)

    Werner, H.; Bublak, D.; Goebel, U.; Henschke, B.; Bensch, W.; Schloegl, R.

    1992-01-01

    The fullerenes can be described as molecular analogues of activated charcoal with a large inner surface. Accordingly, in the solid state, C 60 adsorbs organic molecules and oxygen from the air. The conditions of the production, purification, and storage therefore dictate the electronic and dynamic properties of the van der Waals crystals. Obtaining fullerene samples with defined and reproducible properties is more difficult than previously thought. (orig.) [de

  2. C-60 as a Faraday cage

    OpenAIRE

    Delaney, Paul; Greer, J.C.

    2004-01-01

    Endohedral fullerenes have been proposed for a number of technological uses, for example, as a nanoscale switch, memory bit and as qubits for quantum computation. For these technology applications, it is important to know the ease with which the endohedral atom can be manipulated using an applied electric field. We find that the Buckminsterfullerene (C-60) acts effectively as a small Faraday cage, with only 25% of the field penetrating the interior of the molecule. Thus influencing the atom i...

  3. Solvent friction effects propagate over the entire protein molecule through low-frequency collective modes.

    Science.gov (United States)

    Moritsugu, Kei; Kidera, Akinori; Smith, Jeremy C

    2014-07-24

    Protein solvation dynamics has been investigated using atom-dependent Langevin friction coefficients derived directly from molecular dynamics (MD) simulations. To determine the effect of solvation on the atomic friction coefficients, solution and vacuum MD simulations were performed for lysozyme and staphylococcal nuclease and analyzed by Langevin mode analysis. The coefficients thus derived are roughly correlated with the atomic solvent-accessible surface area (ASA), as expected from the fact that friction occurs as the result of collisions with solvent molecules. However, a considerable number of atoms with higher friction coefficients are found inside the core region. Hence, the influence of solvent friction propagates into the protein core. The internal coefficients have large contributions from the low-frequency modes, yielding a simple picture of the surface-to-core long-range damping via solvation governed by collective low-frequency modes. To make use of these findings in implicit-solvent modeling, we compare the all-atom friction results with those obtained using Langevin dynamics (LD) with two empirical representations: the constant-friction and the ASA-dependent (Pastor-Karplus) friction models. The constant-friction model overestimates the core and underestimates the surface damping whereas the ASA-dependent friction model, which damps protein atoms only on the solvent-accessible surface, reproduces well the friction coefficients for both the surface and core regions observed in the explicit-solvent MD simulations. Therefore, in LD simulation, the solvent friction coefficients should be imposed only on the protein surface.

  4. Fabrication of C60/amorphous carbon superlattice structures

    International Nuclear Information System (INIS)

    Kojima, Nobuaki; Ohshita, Yoshio; Yamaguchi, Masafumi

    2001-01-01

    The nitrogen doping effects in C 60 films by RF plasma source was investigated, and it was found that the nitrogen ion bombardment broke up C 60 molecules and changed them into amorphous carbon. Based on these results, formation of C 60 /amorphous carbon superlattice structure was proposed. The periodic structure of the resulted films was confirmed by XRD measurements, as the preliminary results of fabrication of the superlattice structure

  5. Photophysics of C60 Colloids

    Science.gov (United States)

    2012-11-28

    nonlinear-optical properties and excited-state dynamics of pristine, oxygen- doped , and photopolymerized C-60 in the solid-state," Physical Review B...C45 (2009). 139. E. A. Brujan, "Numerical investigation on the dynamics of cavitation nanobubbles," Microfluidics and Nanofluidics 11(5), 511-517

  6. Is C60 fullerite harder than diamond?

    International Nuclear Information System (INIS)

    Blank, V.; Popov, M.; Buga, S.; Davydov, V.; Denisov, V.N.; Ivlev, A.N.; Mavrin, B.N.; Agafonov, V.; Ceolin, R.; Szwarc, H.; Rassat, A.

    1994-01-01

    Raman spectra of C 60 fullerite at pressures up to 37 GPa with shear deformation are studied. We have found two states at high pressures, that persist after pressure release and have various transparencies in the near IR region. The nontransparent state is formed at 6-18 GPa and has a Raman spectrum with broadened bands at frequencies close to those of the initial fullerite. The transparent state was obtained at pressures higher than 18 GPa, and the Raman bands are broadened and overlapping in comparison with those of the nontransparent state. We suppose that C 60 molecules persist in both states. The transparent state of fullerite shows a hardness higher than that of diamond. ((orig.))

  7. Studies of C60 in fossil of dinosaur egg shell

    International Nuclear Information System (INIS)

    Wang Zhenxia; Li Xuepeng; Wang Wenmin; Xu Xunjiang; Tang Zichao; Huang Rongbin; Zheng Lansun

    1998-01-01

    The occurrence of C 60 in unearthed fossil of dinosaur egg shell about 70 million years ago was reported. The results are discussed considering possible effects of the conceivable atmosphere pollution on the growth of fullerene molecules

  8. C60 as a Faraday cage

    Science.gov (United States)

    Delaney, P.; Greer, J. C.

    2004-01-01

    Endohedral fullerenes have been proposed for a number of technological uses, for example, as a nanoscale switch, memory bit and as qubits for quantum computation. For these technology applications, it is important to know the ease with which the endohedral atom can be manipulated using an applied electric field. We find that the Buckminsterfullerene (C60) acts effectively as a small Faraday cage, with only 25% of the field penetrating the interior of the molecule. Thus influencing the atom is difficult, but as a qubit the endohedral atom should be well shielded from environmental electrical noise. We also predict how the field penetration should increase with the fullerene radius.

  9. Computationally derived rules for persistence of C60 nanowires on recumbent pentacene bilayers.

    Science.gov (United States)

    Cantrell, Rebecca A; James, Christine; Clancy, Paulette

    2011-08-16

    The tendency for C(60) nanowires to persist on two monolayers of recumbent pentacene is studied using molecular dynamics (MD) simulations. A review of existing experimental literature for the tilt angle adopted by pentacene on noble metal surfaces shows that studies cover a limited range from 55° to 90°, motivating simulation studies of essentially the entire range of tilt angles (10°-90°) to predict the optimum surface tilt angle for C(60) nanowire formation. The persistence of a 1D nanowire depends sensitively on this tilt angle, the amount of initial tensile strain, and the presence of surface step edges. At room temperature, C(60) nanowires oriented along the pentacene short axes persist for several nanoseconds and are more likely to occur if they reside between, or within, pentacene rows for ϕ ≤ ∼60°. The likelihood of this persistence increases the smaller the tilt angle. Nanowires oriented along the long axes of pentacene molecules are unlikely to form. The limit of stability of nanowires was tested by raising the temperature to 400 K. Nanowires located between pentacene rows survived this temperature rise, but those located initially within pentacene rows are only stable in the range ϕ(1) = 30°-50°. Flatter pentacene surfaces, that is, tilt angles above about 60°, are subject to disorder caused by C(60) molecules "burrowing" into the pentacene surface. An initial strain of 5% applied to the C(60) nanowires significantly decreases the likelihood of nanowire persistence. In contrast, any appreciable surface roughness, even by half a monolayer in height of a third pentacene monolayer, strongly enhances the likelihood of nanowire formation due to the strong binding energy of C(60) molecules to step edges.

  10. C60 as an Atom Trap to Capture Co Adatoms

    DEFF Research Database (Denmark)

    Yang, Peng; Li, Dongzhe; Repain, Vincent

    2015-01-01

    C60 molecules were used to trap Co adatoms and clusters on a Au(111) surface using atomic/molecular manipulation with a scanning tunneling microscope. Two manipulation pathways (successive integration of single Co atoms in one molecule or direct integration of a Co cluster) were found...... to efficiently allow the formation of complexes mixing a C60 molecule with Co atoms. Scanning tunneling spectroscopy reveals the robustness of the pi states of C60 that are preserved after Co trapping. Scanning tunneling microscopy images and density functional theory calculations reveal that dissociated Co...... clusters of up to nine atoms can be formed at the molecule-substrate interface. These results open new perspectives in the interactions between metal adatoms and molecules, for applications in metal-organic devices...

  11. Formation of buckminsterfullerene (C60) in interstellar space

    Science.gov (United States)

    Berné, Olivier; Tielens, Alexander G. G. M.

    2012-01-01

    Buckminsterfullerene (C60) was recently confirmed to be the largest molecule identified in space. However, it remains unclear how, and where this molecule is formed. It is generally believed that C60 is formed from the build up of small carbonaceous compounds, in the hot and dense envelopes of evolved stars. Analyzing infrared observations, obtained by Spitzer and Herschel, we found that C60 is efficiently formed in the tenuous and cold environment of an interstellar cloud illuminated by strong ultraviolet (UV) radiation fields. This implies that another formation pathway, efficient at low densities, must exist. Based on recent laboratory and theoretical studies, we argue that Polycyclic Aromatic Hydrocarbons are converted into graphene, and subsequently C60, under UV irradiation from massive stars. This shows that alternative - top-down - routes are key to understanding the organic inventory in space.

  12. Destruction of C60 films by boron ion bombardment

    International Nuclear Information System (INIS)

    Ren Zhongmin; Du Yuancheng; Ying Zhifeng; Xiong Xiaxing; Li Fuming

    1995-01-01

    C 60 films are bombarded by 100 keV boron ion beams at doses ranging from 3x10 14 to 1x10 16 /cm 2 . The bombarded films are analyzed using Fourier transform infrared spectroscopy (FTIR), Raman spectra and X-ray diffraction (XRD) measurements. Most C 60 soccer-balls in the implanted region in the films are found to be broken at a dose over 1x10 15 /cm 2 , while at a dose less than 6x10 14 /cm 2 a few C 60 molecules remain undestroyed and maintain some crystal structure. The results of the analyses suggest a complete disintegration of a C 60 molecule under B + bombardment. ((orig.))

  13. Influences of atom Ar on Ar at C60 + Ar at C60 collisions

    International Nuclear Information System (INIS)

    Zhao Qiang; Zhou Hongyu; Zhang Fengshou

    2007-01-01

    A semi-emperical molecular dynamics model was developed. The central collisions of C 60 + C 60 and Ar at C 60 + Ar at C 60 at the same incident energy were investigated within this model. The fullerene dimers could be formed by a self-assembly of C 60 fullerene, and the new fullerene structure like 'peanut' could be formed by a self-assembly of Ar at C 60 . It was found that atom Ar had a great effect on the collision of Ar at C 60 + Ar at C 60 . (authors)

  14. Iron ion implantation into C60 layer

    International Nuclear Information System (INIS)

    Racz, R.; Biri, S.; Csik, A.; Vad, K.

    2011-01-01

    Complete text of publication follows. The soccer ball shaped carbon molecule consisting of 60 carbon atoms (C 60 , fullerene) was discovered in 1985. Since that time the fullerene has become intensively studied. This special molecule has much potential in medical care, biotechnology and nanotechnology. We are motivated to produce special type fullerenes, so called endohedral fullerenes (some alien atoms are encapsulated inside the fullerene cage). The spring of our motivation is that the Fe at C 60 could be applied as a contrast material for MRI (Magnetic Resonance Imaging) or microwave heat therapy. One way to make X at C 60 is the surface production using an ECRIS (Electron Cyclotron Resonance Ion Source). An evaporated or preprepared fullerene layer is irradiated by ions to form a new material during the implantation. By this method several kinds of atomic species, such as Li, Na, K, Rb, Xe were encapsulated into the fullerenes. However evidence for the Fe at C 60 has not been found yet. During the analysis of the irradiated samples three questions must be answered. 1. Are there iron atoms in the layer and where? 2. Does the iron bond to the fullerene? 3. How does the iron bond to the fullerene, inside or outside? Using different investigation tools, SNMS (Secondary Neural Mass Spectrometer), MALDI-TOF (Matrix Assisted Laser Desorption Ionization Time of Flight), XPS (Xray Photoelectron Spectroscopy) or HPLC (High-Performance Liquid Chromatography), all these questions could be clarified step by step. In this paper we made the first steps to answer the first question: fullerene layers irradiated by iron ion beam delivered by the ATOMKI-ECRIS have been analyzed by the ATOMKI-SNMS. The evaporated 90 - 120 nm thick fullerene layers on Si holder were irradiated by Fe 5+ and Fe + ion beams produced from Ferrocene vapor. Samples were irradiated with two different doses (5 10 18 ion/cm 3 and 10 22 ion/cm 3 ) at four ion energies (65 keV, 6.5 keV, 0.2 keV and two of

  15. Reducing HAuCl4 by the C60 dianion: C60-directed self-assembly of gold nanoparticles into novel fullerene bound gold nanoassemblies

    International Nuclear Information System (INIS)

    Liu Wei; Gao Xiang

    2008-01-01

    The C 60 dianion is used to reduce tetrachloroauric acid (HAuCl 4 ) for the first time; three-dimensional C 60 bound gold (Au-C 60 ) nanoclusters are obtained from C 60 -directed self-assembly of gold nanoparticles due to the strong affinities of Au-C 60 and C 60 -C 60 . The process was monitored in situ by UV-vis-NIR spectroscopy. The resulting Au-C 60 nanoclusters were characterized using transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy-dispersive spectroscopy (EDS), x-ray powder diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and FT-IR and Raman spectroscopies. TEM demonstrates the formation of 3D nanonetwork aggregates, which are composed of discrete gold nanocores covered with a C 60 monolayer. The SAED and XRD patterns indicate that the gold nanocores inside the capped C 60 molecules belong to the face-centred cubic crystal structure, while the C 60 molecules are amorphous. The EDS and XPS measurements validate that the Au-C 60 nanoclusters contain only Au and C elements and Au 3+ is reduced to Au 0 . FT-IR spectroscopy shows the chemiadsorption of C 60 to the gold nanocores, while Raman spectroscopy demonstrates the electron transfer from the gold nanocores to the chemiadsorbed C 60 molecules. Au-C 60 nanoclusters embedded in tetraoctyl-n-ammonium bromide (TOAB) on glassy carbon electrodes (GCEs) have been fabricated and have shown stable and well-defined electrochemical responses in aqueous solution

  16. The birth of C60: buckminsterfullerene

    International Nuclear Information System (INIS)

    Kroto, H.

    1993-01-01

    Almost exactly five years after C 60 : Buckminsterfullerene (fullerene-60) was discovered serendipitously during a series of graphite laser vaporization experiments which were designed to simulate the chemistry in a red giant carbon star, the molecule has been isolated in macroscopic amounts. This breakthrough has triggered an explosion of research into its chemical and physical properties. The molecule has already exhibited a wide range of novel phenomena which promise exciting applications. Whether or not applications arise Buckminsterfullerene has a beauty and elegance that has excited the imaginations of scientists and laymen alike. It seems almost impossible to comprehend how the existence of the third well-characterised allotropic form of carbon could have evaded discovery until almost the end of the twentieth century. New fields of chemistry, physics and materials scince have been born and the articles contained in this volume cover some of the fascinating properties that have been uncovered and which pressage exciting implications for the future. This article surveys some of the key events which led to the birth of these new field and serves as an introduction to this volume. (orig.)

  17. Structural transformation of biochar black carbon by C60 superstructure: Environmental implications

    Science.gov (United States)

    Aqueous fullerene C60 nanoparticles (nC60) are frequently considered within the environmental engineering community as the aggregate of 60-carbon molecules. This study employed transmission electron microscopy (TEM) and x-ray diffraction (XRD) to demonstrate that nC60 formed via prolonged stirring ...

  18. Photodetachment of negative C60- ions

    International Nuclear Information System (INIS)

    Amusia, M.Ya.; Baltenkov, A.S.; Krakov, B.G.

    1998-01-01

    A model that describes the electron structure of negative fullerene C 60 - ions is proposed. The model contains only two experimentally observed parameters, namely the fullerene radius and the affinity energy of the electron to neutral C 60 . In the frame of this model, cross sections are calculated of elastic scattering of slow electrons on neutral fullerene, of C 60 - photodetachment near the threshold of this process and of radiative recombination of slow electrons with neutral fullerenes. (orig.)

  19. Electronic Structure of Eu6C60

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-Xiong; LI Hong-Nian; XU Ya-Bo; WANG Peng; ZHANG Wen-Hua; XU Fa-Qiang

    2009-01-01

    We study the valence band of Eu-intercalated C60 by synchrotron radiation photoelectron spectroscopy to un-derstand the ferromagnetism (FM) and the giant magnetoresistance (GMR) of Eu6C60. The results reveal the semiconducting property and the remarkable 5d6s-π hybridization. Eu-C60 bonding has both ionic and covalent contributions. No more than half the 5d6s electrons transfer from Eu to the LUMO derived band of C60, and the LUMO+1 derived band is not filled. The remaining valence electrons of Eu, together with some π (LUMO, HOMO and HOMO-1) electrons, constitute the covalent bond. The electronic structure implies that the magnetic coupling in Eu6C60 should be through the intra-atomic f-sd exchange and the medium of the π electrons. The possibility of the GMR being tunnelling magnetoresistance is ruled out.

  20. Structural model and trans-interaction of the entire ectodomain of the olfactory cell adhesion molecule

    DEFF Research Database (Denmark)

    Kulahin, Nikolaj; Kristensen, Ole; Rasmussen, Kim K

    2011-01-01

    of six recombinant proteins corresponding to different regions of the ectodomain. The model is the longest experimentally based composite structural model of an entire IgCAM ectodomain. It displays an essentially linear arrangement of IgI-V, followed by bends between IgV and Fn3I and between Fn3I and Fn3...

  1. Laser-assisted deposition of thin C60 films

    DEFF Research Database (Denmark)

    Schou, Jørgen; Canulescu, Stela; Fæster, Søren

    Metal and metal oxide films with controlled thickness from a fraction of a monolayer up more than 1000 nm and known stoichiometry can be produced by pulsed laser deposition (PLD) relatively easily, and (PLD) is now a standard technique in all major research laboratories within materials science...... of the matrix material, anisole, with a concentration of 0.67 wt% C60. At laser fluences below 1.5 J/cm2, a dominant fraction of the film molecules are C60 transferred to the substrate without any fragmentation. High-resolution SEM images of MAPLE deposited films reveal large circular features on the surface...

  2. Electronically excited C 2 from laser photodissociated C 60

    Science.gov (United States)

    Arepalli, S.; Scott, C. D.; Nikolaev, P.; Smalley, R. E.

    2000-03-01

    Spectral and transient emission measurements are made of radiation from products of laser excitation of buckminsterfullerene (C 60) vapor diluted in argon at 973 K. The principal radiation is from the Swan band system of C 2 and, at early times, also from a black-body continuum. Transient measurements indicate two characteristic periods of decay 2 and 50 μs long, with characteristic decay times of ˜0.3 and 5 μs, respectively. The first period is thought to be associated with decomposition and radiative cooling of C 60 molecules or nano-sized carbon particles and the second period continues with decomposition products of laser excited C 60, C 58, C 56, etc.

  3. Fulereno[C60]: química e aplicações Fullerene C60: chemistry and applications

    Directory of Open Access Journals (Sweden)

    Leandro José dos Santos

    2010-01-01

    Full Text Available Fullerene chemistry has become a very active research field in the two last decades, largely because of the exceptional properties of the C60 molecule and the variety of fullerene derivatives that appear to be possible. In this review, a general analysis of fullerene C60 reactivity is performed. The principal methods for the covalent modification of this fascinating carbon cage are presented. The prospects of using fullerene derivatives as medicinal drugs and photoactive materials in light converting devices are demonstrated.

  4. Rotational dynamics of C60 in Na2RbC60

    International Nuclear Information System (INIS)

    Christides, C.; Prassides, K.; Neumann, D.A.; Copley, J.R.D.; Mizuki, J.; Tanigaki, K.; Hirosawa, I.; Ebbesen, T.W.

    1993-01-01

    We have measured the low-energy neutron inelastic-scattering (NIS) spectra of superconducting Na 2 RbC 60 in the temperature range 50-350 K. Well-defined librational peaks are observed at 50 K at 2.83(17) meV (FWHM = 1.7(5) meV). They soften and broaden with increasing temperature. Their behaviour mimics that found in solid C 60 and differs markedly from K 3 C 60 . The rotational barrier for C 60 reorientations in Na 2 RbC 60 is somewhat higher than in pristine C 60 and approximately half as large as in K 3 C 60 . An order-disorder transition is anticipated at a temperature higher than that found in C 60 . (orig.)

  5. Binary molecular layers of C-60 and copper phthalocyanine on Au(111) : Self-organized nanostructuring

    NARCIS (Netherlands)

    Stöhr, Meike; Wagner, Thorsten; Gabriel, Markus; Weyers, Bastian; Möller, Rolf

    The binary molecular system of C-60 and copper phthalocyanine(CuPc) molecules has been investigated by scanning tunneling microscopy (STM) at room temperature and at 50 K. As substrate Au(111) was chosen. When C-60 and CuPc molecules are sequentially deposited, it is found that well-ordered domains

  6. Direct observation of interfacial C60 cluster formation in polystyrene-C60 nanocomposite films

    International Nuclear Information System (INIS)

    Han, Joong Tark; Lee, Geon-Woong; Kim, Sangcheol; Lee, Hae-Jeong; Douglas, Jack F; Karim, Alamgir

    2009-01-01

    Large interfacial C 60 clusters were directly imaged at the supporting film-substrate interface in physically detached polystyrene-C 60 nanocomposite films by atomic force microscopy, confirming the stabilizing mechanism previously hypothesized for thin polymer films. Additionally, we found that the C 60 additive influences basic thermodynamic film properties such as the interfacial energy and the film thermal expansion coefficient.

  7. Interaction between poly(vinyl pyrrolidone) PVP and fullerene C60 at the interface in PVP-C60 nanofluids–A spectroscopic study

    Science.gov (United States)

    Behera, M.; Ram, S.

    2018-03-01

    Fourier transform infrared and Raman bands shows a discernible enhancement in band intensity of C–H stretching, C=O stretching, C–N stretching, C–H2 bending, and C–H2 in-plane bending in PVP molecules in the presence of C60 molecules. Amplification in intensity is ascribed to microscopic interactions results when a donation of nonbonding electron (n) occurs from a “>N–C=O” entity of PVP into a lowest unoccupied molecular orbital of the C60 molecule in PVP-C60 charge transfer (CT) complex. The C=O stretching band intensity (integrated) Vs C60 content plot exhibits a peak near a critical 13.9 μM C60 value owing to percolation effect. Light emission spectra show that even a small addition of 4.63 μM C60 able to suppress the band intensity by ~23% as a result of an energy loss. The integrated band intensity also decreases through a peak near 13.9 μM when plotted against the C60-content. In correlation to the vibration spectra, the maximum effect observed both in light emission and excitation spectra suggests a percolation effect in the CT complex. Exhibition of percolation threshold in C60-PVP donor-acceptor complex will be helpful in optimizing the photovoltaic properties vital for solar cell applications.

  8. Femtosecond Dynamics of Photoexcited C60 Films.

    Science.gov (United States)

    Causa', Martina; Ramirez, Ivan; Martinez Hardigree, Josue F; Riede, Moritz; Banerji, Natalie

    2018-04-19

    The well known organic semiconductor C 60 is attracting renewed attention due to its centimeter-long electron diffusion length and high performance of solar cells containing 95% fullerene, yet its photophysical properties remain poorly understood. We elucidate the dynamics of Frenkel and intermolecular (inter-C 60 ) charge-transfer (CT) excitons in neat and diluted C 60 films from high-quality femtosecond transient absorption (TA) measurements performed at low fluences and free from oxygen or pump-induced photodimerization. We find from preferential excitation of either species that the CT excitons give rise to a strong electro-absorption (EA) signal but are extremely short-lived. The Frenkel exciton relaxation and triplet yield strongly depend on the C 60 aggregation. Finally, TA measurements on full devices with applied electric field allow us to optically monitor the dissociation of CT excitons into free charges for the first time and to demonstrate the influence of cluster size on the spectral signature of the C 60 anion.

  9. Electron Impact Ionization of C60

    International Nuclear Information System (INIS)

    Duenser, B.; Lezius, M.; Scheier, P.; Deutsch, H.; Maerk, T.D.

    1995-01-01

    Absolute partial and total cross sections for the electron impact ionization of C 60 have been measured using a novel approach for the absolute calibration. The results obtained reveal not only an anomalous large parent ion cross section (as compared to the other ionization channels), but also anomalies for the production of multiply charged parent and fragment ions. This special behavior has its origin in the specific electronic and geometric structure of C 60 . Semiclassical calculations for singly charged ions support the measured data

  10. Bridging C60 by silicon: Towards non-Van der Waals C60-based materials

    International Nuclear Information System (INIS)

    Tournus, F.; Masenelli, B.; Melinon, P.; Blase, X.; Perez, A.; Pellarin, M.; Broyer, M.; Flank, A.M.; Lagarde, P.

    2002-01-01

    We report the three-dimensional packing of C 60 clusters stabilized by the addition of Si. X-ray absorption spectroscopy reveals that Si atoms are in an unusual environment: between two C 60 , with ten or more carbon neighbors. According to ab initio calculations, the cohesive energy is about 2 eV per Si atom, much higher than the Van der Waals binding energy between two C 60 . Experiment and calculations both indicate a charge transfer from Si to C 60 . Eventually, the film may have a local decahedral symmetry

  11. Molecular dynamics simulation of carbon nanostructures: The C60 buckminsterfullerene

    International Nuclear Information System (INIS)

    Laszlo, Istvan; Zsoldos, Ibolya

    2012-01-01

    Molecular dynamics calculations can reveal the physical and chemical properties of various carbon nanostructures or can help to devise the possible formation pathways. In our days the most well-known carbon nanostructures are the fullerenes, the nanotubes, and the graphene. The fullerenes and nanotubes can be thought of as being formed from graphene sheets, i.e., single layers of carbon atoms arranged in a honeycomb lattice. Usually the nature does not follow the mathematical constructions. Although the first time the C 60 and the C 70 were produced by laser irradiated graphite, the fullerene formation theories are based on various fragments of carbon chains and networks of pentagonal and hexagonal rings. In the present article various formation pathways for the buckminsterfullerene C 60 molecule will be presented. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Order-disorder transitions in C60 and C70

    International Nuclear Information System (INIS)

    Ramasesha, S.K.

    1995-01-01

    In recent years enormous effort has been put in understanding the chemical and physical properties of C 60 and C 70 . Order-disorder transition in C 60 occurs around 250 K at ambient pressure. At the transition freely rotating molecules get orientationally ordered in a simple cubic lattice. Application of pressure increases the transition temperature at a rate of ≅ 10 K kbar -1 , indicating that pressure favours the ordered state. The DSC and x-ray studies on C 70 indicate two phase transitions, one around 270 K and the other around 340 K at room pressure. These transitions also occur at higher temperatures at higher pressures. Application of pressure is found to lift the degeneracy of the energetically equivalent rotational configurations. The high pressure studies are reviewed in the light of existing literature. (author)

  13. Group lattices with applications to the molecule C60

    International Nuclear Information System (INIS)

    Stuart, S.

    1993-01-01

    A brief introduction to group lattices and their application to the electronic structure of C 6 0 is presented. Group lattice methods with experimental results yield a fairly clear picture of the electronic energy levels. (Author) 7 refs

  14. Structural stability of C60 films under irradiation with swift heavy ions

    International Nuclear Information System (INIS)

    Jin Yunfan; Yao Cunfeng; Wang Zhiguang; Xie Erqing; Song Yin; Sun Youmei; Zhang Chonghong; Liu Jie; Duan Jinglai

    2005-01-01

    In order to investigate the structural stability of fullerene (C 60 ) under swift heavy ion irradiation, the irradiation experiments of thin C 60 films were performed with 22 MeV/amu Fe 56 ions delivered by HIRFL at Lanzhou in China. The irradiated C 60 films were analyzed by means of Raman scattering and Fourier transform infrared (FTIR) spectroscopes. The analysis results indicated that the damage cross-sections σ of the C 60 molecule deduced from the data of the Raman spectra are between 1.1 and 4.5 x 10 -14 cm 2 for the electronic energy loss from 3.5 to 8.7 keV/nm and electronic energy transfer dominates the damage process of C 60 films. The partial recovery of the damage in irradiated C 60 films at certain electronic energy loss is attributed to an annealing effect of strong electronic excitation

  15. Nucleation and growth of C60 overlayers on the Ag/Pt(111) dislocation network surface

    International Nuclear Information System (INIS)

    Ait-Mansour, K; Ruffieux, P; Xiao, W; Fasel, R; Groening, P; Groening, O

    2007-01-01

    We have investigated the room temperature growth of C 60 overlayers on the strainrelief dislocation network formed by two monolayers of Ag on Pt(111) by means of scanning tunneling microscopy. Extended domains of highly ordered dislocation networks with a typical superlattice parameter of 6.8 nm have been prepared, serving as templates for subsequent C 60 depositions. For low C 60 coverages, the molecules decorate the step-edges, where also the first islands nucleate. This indicates that at room temperature the C 60 molecules are sufficiently mobile to cross the dislocation lines and to diffuse to the step-edges. For C 60 coverages of 0.4 monolayer, besides the islands nucleated at the step-edges, C 60 islands also grow in the middle of terraces. The C 60 islands typically extend over several unit cells of the dislocation network and show an unusual orientation of the hexagonally close-packed C 60 lattice as compared to that found on the bare Ag(111) surface. Whereas C 60 grows preferentially in a (2 √3 x 2 √3) R30 0 structure on Ag(111), on the Ag/Pt(111) dislocation network the C 60 lattice adopts an orientation rotated by 30 0 , with the close-packed C 60 rows aligned along the dislocations which themselves are aligned along the Ag(1-10) directions. For higher coverages in the range of 1-2 monolayers, the growth of C 60 continues in a layer-by-layer fashion

  16. C60H- an intermediate in the photochemical reduction of C60 fullerene with triethylamine

    International Nuclear Information System (INIS)

    Stasko, A.; Brezova, V.; Neudeck, A.; Bartl, A.; Dunsch, L.

    1999-01-01

    The systematic investigations on the photo reduction of C 60 fullerene and its derivatives using triethylamine and TiO 2 donors, and also other techniques, verified the formation of C 60 .- . Formation of the mono-anion a narrow EPR line (pp A = 0.1 mT) was observed. During a continuous irradiation line A is replaced with line B having g B - 2.0006 and pp B = 0.04 mT which also vanished under prolonged irradiation. But lines A and B repeated after stopping irradiation. This unusual behaviour was re-investigated in analogous EPR-NIR experiments using now a rapid NIR spectrometer. The band at 996 nm was assigned to C 60 H - . The mechanism of C 60 H - formation is discussed

  17. Quantum mechanics, group theory, and C60

    International Nuclear Information System (INIS)

    Rioux, F.

    1994-01-01

    The recent discovery of a new allotropic form of carbon and its production in macroscopic amounts has generated a tremendous amount of research activity in chemistry, physics, and material science. It has also provided educators with an exciting new vehicle for breathing fresh life into some old, well-established methods and principles. Recently, for example, Boo demonstrated the power of group theory in classifying existing and hypothetical fullerenes by their symmetries. In a similar spirit this note describes a model for the electronic structure of C 60 based on the most elementary principles of quantum mechanics and group theory

  18. Optical High Harmonic Generation in C60

    Science.gov (United States)

    Zhang, Guoping

    2005-03-01

    C60 et al. Physical Review Letters Physical Review B High harmonic generation (HHG) requires a strong laser field, but in a relatively weak laser field is sufficient. Numerical results presented here show while its low order harmonics result from the laser field, its high order ones are mainly from the multiple excitations. Since high order harmonics directly correlate electronic transitions, the HHG spectrum accurately measures transition energies. Therefore, is not only a promising material for HHG, but may also present an opportunity to develop HHG into an electronic structure probing tool. References: G. P. Zhang, 91, 176801 (2003); G. P. Zhang and T. F. George, 68, 165410 (2003); P. B. Corkum, 71, 1994 (1993); G. P. Zhang and Thomas F. George, 93, 147401 (2004); H. Niikura ,ature 417, 917 (2002); ibid. 421, 826 (2003); Y. Mairesse ,cience 302, 1540 (2003); A. Baltuska ,ature 421, 611 (2003).

  19. Degradability of aged aquatic suspensions of C60 nanoparticles

    DEFF Research Database (Denmark)

    Hartmann, Nanna Isabella Bloch; Buendia, Inmaculada M.; Bak, Jimmy

    2011-01-01

    In this study, aged aqueous suspensions of C(60) (nC(60)) were investigated in the respirometric OECD test for ready biodegradability. Two suspensions of nC(60) were prepared by stirring and aged under indirect exposure to sunlight for 36 months. ATR-FTIR analyses confirmed the presence of C(60)-...

  20. Physical properties of C60 intercalated graphite films

    International Nuclear Information System (INIS)

    Nakahara, T; Hosomi, N; Taniguchi, J; Suzuki, M; Sato, T; Abe, K; Kuwahara, D; Ishikawa, M; Kato, M; Miura, K

    2007-01-01

    Recently, Miura and Tsuda have synthesized C 60 intercalated graphite film (C 60 /Gr) and reported that the C 60 /Gr consists of alternating close-packed C 60 monolayers and graphite layers. They also found that its frictional force is minimal up to the loading force of 100 nN using AFM [Miura K and Tsuda D 2005 e-J. Surf. Sci. Nanotech. 3 21] Thus, we have started to study the physical properties of C 60 /Gr and carried out NMR, Raman scattering and specific heat measurements. These results suggest that C 60 in C 60 /Gr rotates at room temperature

  1. Self-Assembly of Individually Addressable Complexes of C-60 and Phthalocyanines on a Metal Surface : Structural and Electronic Investigations

    NARCIS (Netherlands)

    Samuely, Tomas; Liu, Shi-Xia; Haas, Marco; Decurtins, Silvio; Jung, Thomas A.; Stoehr, Meike

    2009-01-01

    The hosting properties of a close-packed layer of phenoxy-substituted phthalocyanine derivatives adsorbed on Ag(III) were investigated for the adsorption of C-60 molecules. The C-60 molecules bind to two clearly distinguishable sites, namely, to the underlying metal substrate in between two adjacent

  2. Chemical potential pinning due to equilibrium electron transfer at metal/C60-doped polymer interfaces

    Science.gov (United States)

    Heller, C. M.; Campbell, I. H.; Smith, D. L.; Barashkov, N. N.; Ferraris, J. P.

    1997-04-01

    We report electroabsorption measurements of the built-in electrostatic potential in metal/C60-doped polymer/metal structures to investigate chemical potential pinning due to equilibrium electron transfer from a metal contact to the electron acceptor energy level of C60 molecules in the polymer film. The built-in potentials of a series of structures employing thin films of both undoped and C60-doped poly[2-methoxy, 5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) were measured. For undoped MEH-PPV, which has an energy gap of about 2.4 eV, the maximum built-in potential is about 2.1 eV, whereas for C60-doped MEH-PPV the maximum built-in potential decreases to 1.5 eV. Electron transfer to the C60 molecules close to the metal interface pins the chemical potential of the metal contact near the electron acceptor energy level of C60 and decreases the built-in potential of the structure. From the systematic dependence of the built-in potential on the metal work function we find that the electron acceptor energy level of C60 in MEH-PPV is about 1.7 eV above the hole polaron energy level of MEH-PPV.

  3. Preparation and biodistribution of radiolabeled fullerene C60 nanocrystals

    International Nuclear Information System (INIS)

    Nikolic, Nadezda; Vranjes-Duric, Sanja; Jankovic, Drina; Dokic, Divna; Mirkovic, Marija; Bibic, Natasa; Trajkovic, Vladimir

    2009-01-01

    The present study describes for the first time a procedure for the radiolabeling of fullerene (C 60 ) nanocrystals (nanoC 60 ) with Na 125 I, as well as the biodistribution of radiolabeled nanoC 60 ( 125 I-nanoC 60 ). The solvent exchange method with tetrahydrofuran was used to make colloidal water suspensions of radiolabeled nanoC 60 particles. The radiolabeling procedure with the addition of Na 125 I to tetrahydrofuran during dissolution of C 60 gave a higher radiochemical yield of radiolabeled nanoC 60 particles in comparison to the second option, in which Na 125 I was added after C 60 was dissolved. Using photon correlation spectroscopy and transmission electron microscopy, 125 I-nanoC 60 particles were found to have a crystalline structure and a mean diameter of 200-250 nm. The 125 I-nanoC 60 had a particularly high affinity for human serum albumin, displaying 95% binding efficiency after 1 h. Biodistribution studies of 125 I-nanoC 60 in rats indicated significant differences in tissue accumulation of 125 I-nanoC 60 and the radioactive tracer Na 125 I. The higher accumulation of radiolabeled nanoC 60 was observed in liver and spleen, while accumulation in thyroid, stomach, lungs and intestines was significantly lower in comparison to Na 125 I. In addition to being useful for testing the biological distribution of nanoC 60 , the described radiolabeling procedure might have possible applications in cancer radiotherapy.

  4. The non-exponential relaxation of the C60 crystal around glass transition temperature

    International Nuclear Information System (INIS)

    Yan, F; Wang, Y.N.

    1999-01-01

    A model of the energy barrier of a molecule between two orientational states in the C 60 crystal, which depends on the neighboring molecules, is first proposed. Based on this model, the orientational relaxation of C 60 molecules around 90 K was simulated with the Monte Carlo method. The simulation results show that the relaxation is slightly non-exponential and can fit the Kohlrausch-Williams-Watts function with the non-exponential factor β = 0.962 ± 0.002, which is equal to the experimental data that has not been explained before. (orig.)

  5. Determination of the displacement cross-section in C-60 fullerene exposed to the gamma rays

    International Nuclear Information System (INIS)

    Leyva, A.; Pinnera, I.; Leyva, D.; Cruz, C.; Abreu, Y.

    2011-01-01

    Using the threshold energy values reported in literature for spherical fullerene C-60 molecules and taking into account the McKinley-Feshbach approach, the effective atomic displacement cross-section in C-60 nanostructures exposed to the gamma rays was estimated. The Kinchin-Pease approximation for the damage function was also considered. These calculations were performed using MCCM code system developed by the authors for the study of gamma radiation damage in solid materials. (Author)

  6. Strain Lattice Imprinting in Graphene by C60 Intercalation at the Graphene/Cu Interface

    NARCIS (Netherlands)

    Monazami, Ehsan; Bignardi, Luca; Rudolf, Petra; Reinke, Petra

    2015-01-01

    Intercalation of C60 molecules at the graphene-substrate interface by annealing leads to amorphous and crystalline intercalated structures. A comparison of topography and electronic structure with wrinkles and moiré patterns confirms intercalation. The intercalated molecules imprint a local

  7. Degradability of aged aquatic suspensions of C60 nanoparticles

    DEFF Research Database (Denmark)

    Hartmann, B.; Buendia, Inmaculada M.; Baun, Anders

    2011-01-01

    While studies of the potential human and environmental effects of C60 and its derivatives are emerging in the scientific literature, the environmental fate of C60 is still largely unknown. In this study, aged aqueous suspensions of C60 (nC60) were investigated in the respirometric OECD test...... for ready biodegradability. Two suspensions of nC60 were prepared by stirring and aged under indirect exposure to sunlight for 36 months, which resulted in relatively stable suspensions with a dark-brown colour. The suspended nC60 could not be extracted into toluene and indicating that the particles were...... no longer present as underivatised nC60 but had undergone a transformation. TEM images and particle tracking analysis showed that the suspension consisted of particle aggregates with a size of 156 nm (SD=54nm) and 139nm (Sd=49), respectively, but also contained smaller aggregates. Samples of the nC60...

  8. Fast heavy ion collisions with C60: Collective excitation

    International Nuclear Information System (INIS)

    Kadhane, Umesh; Kelkar, A.H.; Misra, D.; Kumar, Ajay; Tribedi, L.C.

    2006-01-01

    Ionization and fragmentation of C 60 in collision with 5 MeV/μm O 6+ ions are studied using recoil ion ToF method. Relative ionization cross sections up to C 60 4+ are determined. The qualitative trend for different C 60 charge states was compared against simple plasmon excitation model

  9. Probing Exciton Diffusion and Dissociation in Single-Walled Carbon Nanotube-C60 Heterojunctions

    Energy Technology Data Exchange (ETDEWEB)

    Dowgiallo, Anne-Marie; Mistry, Kevin S.; Johnson, Justin C.; Reid, Obadiah G.; Blackburn, Jeffrey L.

    2016-05-19

    The efficiency of thin-film organic photovoltaic (OPV) devices relies heavily upon the transport of excitons to type-II heterojunction interfaces, where there is sufficient driving force for exciton dissociation and ultimately the formation of charge carriers. Semiconducting single-walled carbon nanotubes (SWCNTs) are strong near-infrared absorbers that form type-II heterojunctions with fullerenes such as C60. Although the efficiencies of SWCNT-fullerene OPV devices have climbed over the past few years, questions remain regarding the fundamental factors that currently limit their performance. In this study, we determine the exciton diffusion length in the C60 layer of SWCNT-C60 bilayer active layers using femtosecond transient absorption measurements. We demonstrate that hole transfer from photoexcited C60 molecules to SWCNTs can be tracked by the growth of narrow spectroscopic signatures of holes in the SWCNT 'reporter layer'. In bilayers with thick C60 layers, the SWCNT charge-related signatures display a slow rise over hundreds of picoseconds, reflecting exciton diffusion through the C60 layer to the interface. A model based on exciton diffusion with a Beer-Lambert excitation profile, as well as Monte Carlo simulations, gives the best fit to the data as a function of C60 layer thickness using an exciton diffusion length of approximately 5 nm.

  10. Orientational Phase Transition Around 274 K in C60 Single Crystal

    Institute of Scientific and Technical Information of China (English)

    徐亚伯; 何丕模; 杨宏顺; 郑萍; 余朝文; 陈兆甲; 张宣嘉; 李文铸

    1994-01-01

    The electrical conductivity of a C60 single crystal around 274 K and the specific heat of C60 crystals from 150 to 340 K have been measured.The delta-like specific heat peak at about 251 K related to the first-order phase transition has been reported.The activation energy change around 274 K and the lambda-like specific heat peak beginning at 270 K and ending at 310 K show that there is an orientational phase transition in fcc C60 crystals above 251 K.By taking the symmetry into consideration and further analyzing lambda-like specific heat peak and the activation energy change around 274 K,the conclusion has been reached that this new phase transition is an orientational structure transition from the merohedral twinning fcc to the orientationally disordered fcc.The temperature of free rotation of C60 molecules is about 281 K.

  11. Advanced carbon-based material C60 modification using partially ionized cluster and energetic beams

    International Nuclear Information System (INIS)

    Du Yuancheng; Ren Zhongmin; Ning Zhifeng; Xu Ning; Li Fuming

    1997-01-01

    Two processes have been undertaken using Partially ionized cluster deposition (PICBD) and energetic ion bombardment beams deposition (IBD) respectively. C 60 films deposited by PICBD at V=0 and 65 V, which result in highly textured close-packed structure in orientation (110) and being more polycrystalline respectively, the resistance of C 60 films to oxygen diffusion contamination will be improved. In the case of PICBD, the ionized C 60 soccer-balls molecules in the evaporation beams will be fragmented in collision with the substrate under the elevated accelerating fields Va. As a new synthetic IBD processing, two low energy (400 and 1000 eV) nitrogen ion beams have been used to bombard C 60 films to synthesize the carbon nitride films

  12. Comparative computational study of interaction of C60-fullerene and tris-malonyl-C60-fullerene isomers with lipid bilayer: relation to their antioxidant effect.

    Directory of Open Access Journals (Sweden)

    Marine E Bozdaganyan

    Full Text Available Oxidative stress induced by excessive production of reactive oxygen species (ROS has been implicated in the etiology of many human diseases. It has been reported that fullerenes and some of their derivatives-carboxyfullerenes-exhibits a strong free radical scavenging capacity. The permeation of C60-fullerene and its amphiphilic derivatives-C3-tris-malonic-C60-fullerene (C3 and D3-tris-malonyl-C60-fullerene (D3-through a lipid bilayer mimicking the eukaryotic cell membrane was studied using molecular dynamics (MD simulations. The free energy profiles along the normal to the bilayer composed of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC for C60, C3 and D3 were calculated. We found that C60 molecules alone or in clusters spontaneously translocate to the hydrophobic core of the membrane and stay inside the bilayer during the whole period of simulation time. The incorporation of cluster of fullerenes inside the bilayer changes properties of the bilayer and leads to its deformation. In simulations of the tris-malonic fullerenes we discovered that both isomers, C3 and D3, adsorb at the surface of the bilayer but only C3 tends to be buried in the area of the lipid headgroups forming hydrophobic contacts with the lipid tails. We hypothesize that such position has implications for ROS scavenging mechanism in the specific cell compartments.

  13. C60-pentacene network formation by 2-D co-crystallization.

    Science.gov (United States)

    Jin, Wei; Dougherty, Daniel B; Cullen, William G; Robey, Steven; Reutt-Robey, Janice E

    2009-09-01

    We report experiments highlighting the mechanistic role of mobile pentacene precursors in the formation of a network C(60)-pentacene co-crystalline structure on Ag(111). This co-crystalline arrangement was first observed by low temperature scanning tunneling microscopy (STM) by Zhang et al. (Zhang, H. L.; Chen, W.; Huang, H.; Chen, L.; Wee, A. T. S. J. Am. Chem. Soc. 2008, 130, 2720-2721). We now show that this structure forms readily at room temperature from a two-dimensional (2-D) mixture. Pentacene, evaporated onto Ag(111) to coverages of 0.4-1.0 ML, produces a two-dimensional (2-D) gas. Subsequently deposited C(60) molecules combine with the pentacene 2-D gas to generate a network structure, consisting of chains of close-packed C(60) molecules, spaced by individual C(60) linkers and 1 nm x 2.5 nm pores containing individual pentacene molecules. Spontaneous formation of this stoichiometric (C(60))(4)-pentacene network from a range of excess pentacene surface coverage (0.4 to 1.0 ML) indicates a self-limiting assembly process. We refine the structure model for this phase and discuss the generality of this co-crystallization mechanism.

  14. Using the graphene Moiré pattern for the trapping of C60 and homoepitaxy of graphene.

    Science.gov (United States)

    Lu, Jiong; Yeo, Pei Shan Emmeline; Zheng, Yi; Yang, Zhiyong; Bao, Qiaoliang; Gan, Chee Kwan; Loh, Kian Ping

    2012-01-24

    The graphene Moiré superstructure offers a complex landscape of humps and valleys to molecules adsorbing and diffusing on it. Using C(60) molecules as the classic hard sphere analogue, we examine its assembly and layered growth on this corrugated landscape. At the monolayer level, the cohesive interactions of C(60) molecules adsorbing on the Moiré lattice freeze the molecular rotation of C(60) trapped in the valley sites, resulting in molecular alignment of all similarly trapped C(60) molecules at room temperature. The hierarchy of adsorption potential well on the Moiré lattice causes diffusion-limited dendritic growth of C(60) films, as opposed to isotropic growth observed on a smooth surface like graphite. Due to the strong binding energy of the C(60) film, part of the dentritic C(60) films polymerize at 850 K and act as solid carbon sources for graphene homoepitaxy. Our findings point to the possibility of using periodically corrugated graphene in molecular spintronics due to its ability to trap and align organic molecules at room temperature. © 2011 American Chemical Society

  15. Growth of C60 thin films on Al2O3/NiAl(100) at early stages

    Science.gov (United States)

    Hsu, S.-C.; Liao, C.-H.; Hung, T.-C.; Wu, Y.-C.; Lai, Y.-L.; Hsu, Y.-J.; Luo, M.-F.

    2018-03-01

    The growth of thin films of C60 on Al2O3/NiAl(100) at the earliest stage was studied with scanning tunneling microscopy and synchrotron-based photoelectron spectroscopy under ultrahigh-vacuum conditions. C60 molecules, deposited from the vapor onto an ordered thin film of Al2O3/NiAl(100) at 300 K, nucleated into nanoscale rectangular islands, with their longer sides parallel to direction either [010] or [001] of NiAl. The particular island shape resulted because C60 diffused rapidly, and adsorbed and nucleated preferentially on the protrusion stripes of the crystalline Al2O3 surface. The monolayer C60 film exhibited linear protrusions of height 1-3 Å, due to either the structure of the underlying Al2O3 or the lattice mismatch at the boundaries of the coalescing C60 islands; such protrusions governed also the growth of the second layer. The second layer of the C60 film grew only for a C60 coverage >0.60 ML, implying a layer-by-layer growth mode, and also ripened in rectangular shapes. The thin film of C60 was thermally stable up to 400 K; above 500 K, the C60 islands dissociated and most C60 desorbed.

  16. Auger electron spectroscopy of the surface of a pipe-like solid C60+18n

    International Nuclear Information System (INIS)

    Khvostov, V.V.; Chernozatonskij, L.A.; Kosakovskaya, Z.Ya.; Babaev, V.V.; Guseva, M.B.

    1992-01-01

    Auger and electron energy loss spectra obtained when probing the surface of nanofiber carbon material by an electron beam point out to C 60 football-type of covers with the outlet to the surface of nanopipe carbon molecules

  17. Temperature-dependent chemisorption of C60 on Mo(110) : precursors to cage destruction

    NARCIS (Netherlands)

    Hunt, Michael R.C.; Rajogopal, Aparna; Caudano, Roland; Rudolf, Petra

    2000-01-01

    The catalytically promoted decomposition of C60 has recently been observed on a variety of surfaces upon which the molecule can chemisorb strongly. It is now becoming clear that destruction occurs via conversion of a relatively weakly bound state arising from room-temperature adsorption into a

  18. The electronic structure of C60 and its derivatives

    International Nuclear Information System (INIS)

    Lichtenberger, D.L.; Rempe, M.E.; Gruhn, N.E.; Wright, L.L.

    1993-01-01

    Molecular orbital calculations are used to examine the electronic structure of C 60 and its interaction with metals and some other atoms. The bonding capabilities of the η 5 , η 6 , and the two possible η 2 sites of C 60 to metals are probed with Fenske-Hall calculations of a silver cation bound in those positions. These results are compared to the bonding capabilities of cyclopentadiene, benzene and ethylene, respectively. It is found that the silver cation bonding to C 60 is favored at the η 2 that is shared between five-membered rings, but that the silver cation bonds more favorably to ethylene than to the η 2 site of C 60 . The electronic structure of the known platinum compound, C 60 Pt(phosphine) 2 , where the bonding is also to this η 2 site, is investigated and compared to the electronic structure of the corresponding ethylene complex. In this more electron-rich metal case, the bonding of the C 60 and ethylene are very similar. A calculation on C 60 OsO 4 (NH 3 ) 2 , where C 60 is bound to two oxygens, shows that the orbital composition correlates with the observed NMR shifts of the carbon atoms. The calculations are used to clarify the interpretations of experimental data obtained from STM, NMR, PES and reactivity. The latest results of these electronic studies will be presented

  19. Tunneling anisotropic magnetoresistance in C60-based organic spintronic systems

    NARCIS (Netherlands)

    Wang, Kai; Sanderink, Johannes G.M.; Bolhuis, Thijs; van der Wiel, Wilfred Gerard; de Jong, Machiel Pieter

    2014-01-01

    C 60 fullerenes are interesting molecular semiconductors for spintronics since they exhibit weak spin-orbit and hyperfine interactions, which is a prerequisite for long spin lifetimes. We report spin-polarized transport in spin-valve-like structures containing ultrathin (<10 nm) C 60 layers,

  20. Growth and Potential Damage of Human Bone-Derived Cells Cultured on Fresh and Aged C60/Ti Films

    Science.gov (United States)

    Kopova, Ivana; Lavrentiev, Vasily; Vacik, Jiri; Bacakova, Lucie

    2015-01-01

    Thin films of binary C60/Ti composites, with various concentrations of Ti ranging from ~ 25% to ~ 70%, were deposited on microscopic glass coverslips and were tested for their potential use in bone tissue engineering as substrates for the adhesion and growth of bone cells. The novelty of this approach lies in the combination of Ti atoms (i.e., widely used biocompatible material for the construction of stomatological and orthopedic implants) with atoms of fullerene C60, which can act as very efficient radical scavengers. However, fullerenes and their derivatives are able to generate harmful reactive oxygen species and to have cytotoxic effects. In order to stabilize C60 molecules and to prevent their possible cytotoxic effects, deposition in the compact form of Ti/C60 composites (with various Ti concentrations) was chosen. The reactivity of C60/Ti composites may change in time due to the physicochemical changes of molecules in an air atmosphere. In this study, we therefore tested the dependence between the age of C60/Ti films (from one week to one year) and the adhesion, morphology, proliferation, viability, metabolic activity and potential DNA damage to human osteosarcoma cells (lines MG-63 and U-2 OS). After 7 days of cultivation, we did not observe any negative influence of fresh or aged C60/Ti layers on cell behavior, including the DNA damage response. The presence of Ti atoms resulted in improved properties of the C60 layers, which became more suitable for cell cultivation. PMID:25875338

  1. Sputtering of thin benzene and polystyrene overlayers by keV Ga and C60 bombardment

    International Nuclear Information System (INIS)

    Czerwinski, B.; Delcorte, A.; Garrison, B.J.; Samson, R.; Winograd, N.; Postawa, Z.

    2006-01-01

    The mechanisms of ion-stimulated desorption of thin organic overlayers deposited on metal substrates by mono- and polyatomic projectiles are examined using molecular dynamics (MD) computer simulations. A monolayer of polystyrene tetramers (PS4) physisorbed on Ag{1 1 1} is irradiated by 15 keV Ga and C 60 projectiles at normal incidence. The results are compared with the data obtained for a benzene overlayer to investigate the differences in sputtering mechanisms of weakly and strongly bound organic molecules. The results indicate that the sputtering yield decreases with the increase of the binding energy and the average kinetic energy of parent molecules is shifted toward higher kinetic energy. Although the total sputtering yield of organic material is larger for 15 keV C 60 , the impact of this projectile leads to a significant fragmentation of ejected species. As a result, the yield of the intact molecules is comparable for C 60 and Ga projectiles. Our data indicate that chemical analysis of the very thin organic films performed by detection of sputtered neutrals will not benefit from the use of C 60 projectiles

  2. Enantioanalysis of S-deprenyl using enantioselective, potentiometric membrane electrodes based on C60 derivatives

    International Nuclear Information System (INIS)

    Stefan-van Staden, Raluca-Ioana

    2010-01-01

    Enantioselective, potentiometric membrane electrodes based on (1,2-methanofullerene C 60 )-61-carboxylic acid, diethyl (1,2-methanofullerene C 60 )-61-61-dicarboxylate and tert-butyl (1,2-methanofullerene C 60 )-61-carboxylic acid were proposed for the enantioanalysis of S-deprenyl in pharmaceutical compounds. Molecular modeling calculations were performed to prove the reliability of the proposed electrodes. The different characteristics involved in this analysis were explained, namely (i) the stability of each molecule using total energy, hardness and dipole moment, and (ii) the explanation of the mechanism of interaction using intermolecular forces (moderate hydrogen bond interactions), atomic charges and electrostatic potential. Electronic structures as well as molecular interaction have been investigated using Hartree-Fock theory, 3-21G(*) basis set. Stability and feasibility of all the generated structures were supported by their respective energy minima and fundamental frequencies.

  3. Carbon fullerenes (C60s) can induce inflammatory responses in the lung of mice

    International Nuclear Information System (INIS)

    Park, Eun-Jung; Kim, Hero; Kim, Younghun; Yi, Jongheop; Choi, Kyunghee; Park, Kwangsik

    2010-01-01

    Fullerenes (C60s) occur in the environment due to natural and anthropogenic sources such as volcanic eruptions, forest fires, and the combustion of carbon-based materials. Recently, production and application of engineered C60s have also rapidly increased in diverse industrial fields and biomedicine due to C60' unique physico-chemical properties, so toxicity assessment on environmental and human health is being evaluated as a valuable work. However, data related to the toxicity of C60s have not been abundant up to now. In this study, we studied the immunotoxic mechanism and change of gene expression caused by the instillation of C60s. As a result, C60s induced an increase in sub G1 and G1 arrest in BAL cells, an increase in pro-inflammatory cytokines such as IL-1, TNF-α, and IL-6, and an increase of Th1 cytokines such as IL-12 and IFN-r in BAL fluid. In addition, IgE reached the maximum at 1 day after treatment in both BAL fluid and the blood, and decreased in a time-dependent manner. Gene expression of the MHC class II (H2-Eb1) molecule was stronger than that of the MHC class I (H2-T23), and an increase in T cell distribution was also observed during the experiment period. Furthermore, cell infiltration and expression of tissue damage related genes in lung tissue were constantly observed during the experiment period. Based on this, C60s may induce inflammatory responses in the lung of mice.

  4. Disintegration of C60 by Xe ion irradiation

    International Nuclear Information System (INIS)

    Kalish, R.; Samoiloff, A.; Hoffman, A.; Uzan-Saguy, C.

    1993-01-01

    The Changes in resistivity of fullerene (C 60 ) films subject to 320 keV Xe ion irradiation are investigated as a function of ion dose. From a comparison of this dependence with similar data on other Xe irradiated C containing insulating materials and with data on C implanted fused quartz, it is concluded that upon ion impact C 60 clusters completely disintegrate. This disintegration releases about 60 C atoms which disperse amongst the remaining intact C 60 spheres giving rise to hopping conductivity between isolated C atoms. 16 refs., 3 figs

  5. Affine Fullerene C60 in a GS-Quasigroup

    Directory of Open Access Journals (Sweden)

    Vladimir Volenec

    2014-01-01

    Full Text Available It will be shown that the affine fullerene C60, which is defined as an affine image of buckminsterfullerene C60, can be obtained only by means of the golden section. The concept of the affine fullerene C60 will be constructed in a general GS-quasigroup using the statements about the relationships between affine regular pentagons and affine regular hexagons. The geometrical interpretation of all discovered relations in a general GS-quasigroup will be given in the GS-quasigroup C(1/2(1+5.

  6. Crystallinity and properties of C60 nanotubes improved by annealing and alcohol-soaking

    Science.gov (United States)

    Naito, K.; Matsuishi, K.

    2009-04-01

    Well-uniformed C60 nanotubes were grown at -20 °C with irradiation of red light using C60-saturated pyridine solution and isopropyl alcohol by a liquid-liquid interfacial precipitation method without ultrasonic pulverization. We attempted to improve their crystallinity by two post-treatments; thermal annealing and alcohol-soaking. The crystallinity of as-grown and dried C60 nanotubes, which was poor due to the evaporation of solvent molecules from crystals in the drying process, was improved by annealing around 220 °C for 5 hours in vacuum. Dramatic improvement of crystallinity of as-grown samples was achieved by soaking into methanol and then drying in air. Raman, infrared and X-ray diffraction results suggest that the methanol-soaked samples exhibit a solvated tetragonal structure. The crystallinity improved by methanol-soaking did not degrade after removal of methanol molecules from samples by thermal annealing. Photo-polymerization of the structurally-improved C60 nanotubes was examined to investigate an effect of crystallinity on the polymerization kinetics.

  7. Crystallinity and properties of C60 nanotubes improved by annealing and alcohol-soaking

    International Nuclear Information System (INIS)

    Naito, K; Matsuishi, K

    2009-01-01

    Well-uniformed C 60 nanotubes were grown at -20 deg. C with irradiation of red light using C 60 -saturated pyridine solution and isopropyl alcohol by a liquid-liquid interfacial precipitation method without ultrasonic pulverization. We attempted to improve their crystallinity by two post-treatments; thermal annealing and alcohol-soaking. The crystallinity of as-grown and dried C 60 nanotubes, which was poor due to the evaporation of solvent molecules from crystals in the drying process, was improved by annealing around 220 deg. C for 5 hours in vacuum. Dramatic improvement of crystallinity of as-grown samples was achieved by soaking into methanol and then drying in air. Raman, infrared and X-ray diffraction results suggest that the methanol-soaked samples exhibit a solvated tetragonal structure. The crystallinity improved by methanol-soaking did not degrade after removal of methanol molecules from samples by thermal annealing. Photo-polymerization of the structurally-improved C 60 nanotubes was examined to investigate an effect of crystallinity on the polymerization kinetics.

  8. Estimation of the parameters of cytotoxicity of fullerene C60 and C60-containing composites in vitro

    International Nuclear Information System (INIS)

    Priluts'ka, S.V.; Grinyuk, Yi.Yi.; Golub, O.A.; Matishevs'ka, O.P.

    2006-01-01

    The influence of fullerene C 60 and C 60 -containing composites (on the basis of aminopropylaerosyl (ApA)) on the stability of erythrocytes to acid haemolysis and the viability of thymocytes, ascite forms of Erlich and leucosis L1210 cells is studied. The obtained results indicate the possibility to use ApA as a matrix for conjugation with other elements and for the further biological studies of composites photosensitizing the effect

  9. Polarizability of KC60: Evidence for Potassium Skating on the C60 Surface

    Science.gov (United States)

    Rayane, D.; Antoine, R.; Dugourd, Ph.; Benichou, E.; Allouche, A. R.; Aubert-Frécon, M.; Broyer, M.

    2000-02-01

    We present the first measurement of the polarizability and the permanent dipole moment of isolated KC60 molecules by molecular beam deflection technique. We have obtained a value of 2506+/-250 Å3 for the polarizability at room temperature. The addition of a potassium atom enhances by more than a factor of 20 the polarizability of a pure C60 molecule. This very high polarizability and the lack of observed permanent dipole show that the apparent polarizability of KC60 is induced by the free skating of the potassium atom on the C60 surface, resulting in a statistical orientation of the dipole. The results are interpreted with a simple model similar to the Langevin theory for paramagnetic systems.

  10. Influence of the aggregate state on band structure and optical properties of C60 computed with different methods

    Science.gov (United States)

    Pal, Amrita; Arabnejad, Saeid; Yamashita, Koichi; Manzhos, Sergei

    2018-05-01

    C60 and C60 based molecules are efficient acceptors and electron transport layers for planar perovskite solar cells. While properties of these molecules are well studied by ab initio methods, those of solid C60, specifically its optical absorption properties, are not. We present a combined density functional theory-Density Functional Tight Binding (DFTB) study of the effect of solid state packing on the band structure and optical absorption of C60. The valence and conduction band edge energies of solid C60 differ on the order of 0.1 eV from single molecule frontier orbital energies. We show that calculations of optical properties using linear response time dependent-DFT(B) or the imaginary part of the dielectric constant (dipole approximation) can result in unrealistically large redshifts in the presence of intermolecular interactions compared to available experimental data. We show that optical spectra computed from the frequency-dependent real polarizability can better reproduce the effect of C60 aggregation on optical absorption, specifically with a generalized gradient approximation functional, and may be more suited to study effects of molecular aggregation.

  11. Growth of α-sexithiophene nanostructures on C60 thin film layers

    DEFF Research Database (Denmark)

    Radziwon, Michal Jędrzej; Madsen, Morten; Balzer, Frank

    2014-01-01

    Organic molecular beam grown -sexithiophene (-6T) forms nanostructured thin films on buckminsterfullerene (C60) thin film layers. At substrate temperatures of 300K during growth a rough continuous film is observed, which develop to larger elongated islands and dendritic- as well as needle like ...... fluorescence polarimetry measurements the in-plane orientation of the crystalline sites within the needle like structures is determined. The polarimetry investigations strongly indicate that the needle like structures consist of lying molecules....

  12. Effect of Polarization on the Mobility of C60: A Kinetic Monte Carlo Study.

    Science.gov (United States)

    Volpi, Riccardo; Kottravel, Sathish; Nørby, Morten Steen; Stafström, Sven; Linares, Mathieu

    2016-02-09

    We present a study of mobility field and temperature dependence for C60 with Kinetic Monte Carlo simulations. We propose a new scheme to take into account polarization effects in organic materials through atomic induced dipoles on nearby molecules. This leads to an energy correction for the single site energies and to an external reorganization happening after each hopping. The inclusion of polarization allows us to obtain a good agreement with experiments for both mobility field and temperature dependence.

  13. Van der Waals cohesion and plasmon excitations in C60 fullerite

    International Nuclear Information System (INIS)

    Lambin, P.; Lucas, A.A.

    1993-01-01

    The Van der Waals cohesive energy of C 60 fullerite is evaluated from the zero-point energy of multipole plasmons fluctuating on the highly-polarizable Bucky balls. These hollow molecules are treated as dielectric shells. The shell material is an isotropic continuum with a dielectric function designed to exhibit the plasmon resonances observed in other forms of solid carbon in the ultraviolet. (orig.)

  14. Asymmetric fission and evaporation of C60r+ (r = 2-4) fullerene ions in ion-C60 collisions: II. Dependence on collisional processes?

    International Nuclear Information System (INIS)

    Rentenier, A; Bordenave-Montesquieu, A; Moretto-Capelle, P; Bordenave-Montesquieu, D

    2004-01-01

    In this paper, a quantitative comparison of our experimental data for the asymmetrical fission (AF) and neutral evaporation of the C 60 molecule under proton impact (part I) is made with data published by other authors and often obtained in rather different collisional systems. The comparison with multicharged ions for which more quantitative data are available is focused on. It is demonstrated that size distributions of fragments, averaged fragment sizes, branching ratios between AF and evaporation or between AF channels, are common to all the collisional systems. Differences only appear when the comparison includes the undissociated stable fullerene ion signals

  15. DC Characterisation of C60 Whiskers and Nanowhiskers

    DEFF Research Database (Denmark)

    Larsson, Michael; Kjelstrup-Hansen, Jakob; Lucyszyn, Stepan

    2007-01-01

    C60 whiskers exhibit increasing conductivity with decreasing diameter. At diameters of 1 mm and below, a single-crystal structure predominates, and enhanced electrical characteristics are expected; however, no supporting data exists in the literature. Here, results of four-point probe measurements......, indicating strong potential for use in organic electronic applications of the future. Repeated current cycling in air is observed to promote sample degradation, possibly due to progressive oxidation of the carbon structure. A micromachined four-point probe is also used to try to establish non...... on C60 whiskers and nanowhiskers with diameters in the range 650 nm to 1.3 mm are reported for the first time. Samples are attached to pre-patterned planar and raised electrodes using FIB-deposited tungsten. A low resistivity of 3 Wcm is measured in air, on a C60 whisker having a diameter of 650 nm...

  16. Nucleation of C60 on ultrathin SiO2

    Science.gov (United States)

    Conrad, Brad; Groce, Michelle; Cullen, William; Pimpinelli, Alberto; Williams, Ellen; Einstein, Ted

    2012-02-01

    We utilize scanning tunneling microscopy to characterize the nucleation, growth, and morphology of C60 on ultrathin SiO2 grown at room temperature. C60 thin films are deposited in situ by physical vapor deposition with thicknesses varying from <0.05 to ˜1 ML. Island size and capture zone distributions are examined for a varied flux rate and substrate deposition temperature. The C60 critical nucleus size is observed to change between monomers and dimers non-monotonically from 300 K to 500 K. Results will be discussed in terms of recent capture zone studies and analysis methods. Relation to device fabrication will be discussed. doi:10.1016/j.susc.2011.08.020

  17. CuPc/C60 heterojunction thin film optoelectronic devices

    International Nuclear Information System (INIS)

    Murtaza, Imran; Karimov, Khasan S.; Qazi, Ibrahim

    2010-01-01

    The optoelectronic properties of heterojunction thin film devices with ITO/CuPc/C 60 /Al structure have been investigated by analyzing their current-voltage characteristics, optical absorption and photocurrent. In this organic photovoltaic device, CuPc acts as an optically active layer, C 60 as an electron-transporting layer and ITO and Al as electrodes. It is observed that, under illumination, excitons are formed, which subsequently drift towards the interface with C 60 , where an internal electric field is present. The excitons that reach the interface are subsequently dissociated into free charge carriers due to the electric field present at the interface. The experimental results show that in this device the total current density is a function of injected carriers at the electrode-organic semiconductor surface, the leakage current through the organic layer and collected photogenerated current that results from the effective dissociation of excitons. (semiconductor devices)

  18. Effect of heavy ion irradiation on C 60

    Science.gov (United States)

    Lotha, S.; Ingale, A.; Avasthi, D. K.; Mittal, V. K.; Mishra, S.; Rustagi, K. C.; Gupta, A.; Kulkarni, V. N.; Khathing, D. T.

    1999-06-01

    Thin films of C 60 were subjected to swift heavy ion irradiation spanning the region from 2 to 11 keV/nm of electronic excitation. Studies of the irradiated films by Raman spectroscopy indicated polymerization and damage of the film with an ion fluence. The ion track radii are estimated for various ions using the Raman data. Photoluminescence spectroscopy of the irradiated film indicated a decrease in the C 60 phase with a dose, and an increase in the intensity at the 590 nm wavelength, which is attributed to an increase in the oxygen content.

  19. Electronic structure and optical properties of solid C60

    International Nuclear Information System (INIS)

    Mattesini, M.; Ahuja, R.; Sa, L.; Hugosson, H.W.; Johansson, B.; Eriksson, O.

    2009-01-01

    The electronic structure and the optical properties of face-centered-cubic C 60 have been investigated by using an all-electron full-potential method. Our ab initio results show that the imaginary dielectric function for high-energy values looks very similar to that of graphite, revealing close electronic structure similarities between the two systems. We have also identified the origin of different peaks in the dielectric function of fullerene by means of the calculated electronic density of states. The computed optical spectrum compares fairly well with the available experimental data for the Vis-UV absorption spectrum of solid C 60 .

  20. Detection of C60 and C70 in a young planetary nebula.

    Science.gov (United States)

    Cami, Jan; Bernard-Salas, Jeronimo; Peeters, Els; Malek, Sarah Elizabeth

    2010-09-03

    In recent decades, a number of molecules and diverse dust features have been identified by astronomical observations in various environments. Most of the dust that determines the physical and chemical characteristics of the interstellar medium is formed in the outflows of asymptotic giant branch stars and is further processed when these objects become planetary nebulae. We studied the environment of Tc 1, a peculiar planetary nebula whose infrared spectrum shows emission from cold and neutral C60 and C70. The two molecules amount to a few percent of the available cosmic carbon in this region. This finding indicates that if the conditions are right, fullerenes can and do form efficiently in space.

  1. Modification of the Xe 4d giant resonance by the C60 shell in molecular Xe at C60

    International Nuclear Information System (INIS)

    Amusia, M. Ya.; Baltenkov, A. S.; Chernysheva, L. V.; Felfli, Z.; Msezane, A. Z.

    2006-01-01

    It is demonstrated that in photoabsorption of the 4d 10 subshell of a Xe atom in molecular Xe at C 60 , the 4d giant resonance that characterizes the isolated Xe atom is distorted significantly. The reflection of photoelectron waves by the C 60 shell leads to profound oscillations in the photoionization cross section such that the Xe giant resonance is transformed into four strong peaks. Similarly, the angular anisotropy parameters, both dipole and nondipole, are also modified. The method of calculation is based on the approximation of the C 60 shell by an infinitely thin bubble potential that leaves the sum rule for the 4d-electrons almost unaffected, but noticeably modifies the dipole polarizability of the 4d-shell

  2. Free-energy coarse-grained potential for C60

    International Nuclear Information System (INIS)

    Edmunds, D. M.; Tangney, P.; Vvedensky, D. D.; Foulkes, W. M. C.

    2015-01-01

    We propose a new deformable free energy method for generating a free-energy coarse-graining potential for C 60 . Potentials generated from this approach exhibit a strong temperature dependence and produce excellent agreement with benchmark fully atomistic molecular dynamics simulations. Parameter sets for analytical fits to this potential are provided at four different temperatures

  3. Preparation of photovoltaic cells from sexithiophene-C-60 blends

    NARCIS (Netherlands)

    Veenstra, SC; Malliaras, GG; Brouwer, HJ; Esselink, FJ; Krasnikov, VV; vanHutten, PF; Wildeman, J; Jonkman, HT; Sawatzky, GA; Hadziioannou, G; Mohlmann, GR

    1996-01-01

    Large photovoltaic responses have been recently observed in devices based on conjugated polymer-C-60 blends. Their enhanced performance, which relies on the formation of a bicontinuous network of donor-acceptor heterojunctions, is very sensitive to the morphology of the blend. In this paper, we

  4. Assembly of individual TiO2-C60/porphyrin hybrid nanoparticles for enhancement of photoconversion efficiency

    International Nuclear Information System (INIS)

    Jang, Jae Kwon; Park, Se Ho; Song, Hyunjoon; Park, Joon T; Kim, Chulwoo; Ko, Jaejung; Seo, Won Seok

    2011-01-01

    Rational organization of porphyrin and C 60 on the electrode surface in photovoltaic structures is essential to yield high quantum efficiency. In the present work, individual TiO 2 nanoparticles were modified by introducing C 60 and porphyrin units on the surface, and then electrophoretically deposited on an ITO/SnO 2 electrode. The morphology of the photoactive layer on the electrode was significantly different from that of the layer produced as a result of separate deposition of C 60 and porphyrin. The maximum incident photon to current efficiency of the resulting electrode approached 88% at 410 nm, which is the highest value among molecule-based photovoltaic cells reported to date. This indicates that molecular assembly of the C 60 and porphyrin units on the individual nanoparticles through strong chemical attachment is a key factor in improving effective electron transfer between the photoactive units and the electrodes.

  5. Excimer-laser-induced permanent electrical conductivity in solid C60 films

    International Nuclear Information System (INIS)

    Ning, D.; Lou, Q.H.; Dong, J.X.; Wei, Y.R.

    1996-01-01

    After being irradiated in air by a XeCl (308 nm) excimer laser, the electrical conductivity of solid thin-film C 60 has been improved by more than six orders of magnitudes. The products resulting from laser irradiation of C 60 films have been investigated by Raman scattering and the onset of conductivity can be attributed to laser-induced oxygenation and disintegration of the fullerene. Irradiated by ∼40 ns laser pulses with different fluence, products with different microstructure were observed. At lower fluence, the Raman features of microcrystalline graphite and fullerene polymer were observed. At a fluence just below the ablation threshold (36 mJ/cm 2 ), the fullerene molecules in the film were disintegrated completely and transformed to amorphous graphite. (orig.). With 5 figs

  6. Crystallinity of the epitaxial heterojunction of C60 on single crystal pentacene

    Science.gov (United States)

    Tsuruta, Ryohei; Mizuno, Yuta; Hosokai, Takuya; Koganezawa, Tomoyuki; Ishii, Hisao; Nakayama, Yasuo

    2017-06-01

    The structure of pn heterojunctions is an important subject in the field of organic semiconductor devices. In this work, the crystallinity of an epitaxial pn heterojunction of C60 on single crystal pentacene is investigated by non-contact mode atomic force microscopy and high-resolution grazing incidence x-ray diffraction. Analysis shows that the C60 molecules assemble into grains consisting of single crystallites on the pentacene single crystal surface. The in-plane mean crystallite size exceeds 0.1 μm, which is at least five time larger than the size of crystallites deposited onto polycrystalline pentacene thin films grown on SiO2. The results indicate that improvement in the crystal quality of the underlying molecular substrate leads to drastic promotion of the crystallinity at the organic semiconductor heterojunction.

  7. Theoretical modelling of tip effects in the pushing manipulation of C60 on the Si(001) surface

    International Nuclear Information System (INIS)

    Martsinovich, N; Kantorovich, L

    2008-01-01

    We present the results of our theoretical studies on the repulsive (pushing) manipulation of a C 60 molecule on the Si(001) surface with several scanning tunnelling microscopy tips. We show that, for silicon tips, tip-C 60 bonds are formed even with tips that do not initially have dangling bonds, and this tip-C 60 interaction drives the manipulation of the molecule. The details of the atomic structure of the tip and its position relative to the molecule do not have a significant effect on the mechanism and the sequence of adsorption configurations during the pushing manipulation of C 60 along the trough, where the trough itself provides a guiding effect. The pushing manipulation is thus a very robust process that occurs largely independently of the tip structure. On the other hand, the pushing manipulation across an Si-Si dimer row into the neighbouring trough proceeds in a more complex way, with tip deformation and detachment more likely to occur. We demonstrate the role of tip deformation and tip-molecule bond rearrangement in the continuous manipulation of the molecule. Finally, we calculate and analyse the forces acting on the tip during manipulation and identify characteristic patterns

  8. Rb-intercalated C60 compounds studied by photoemission spectroscopies

    International Nuclear Information System (INIS)

    Brambilla, A.; Giovanelli, L.; Vilmercati, P.; Cattoni, A.; Biagioni, P.; Goldoni, A.; Finazzi, M.; Duo, L.

    2005-01-01

    We report on a combined photoemission and inverse photoemission spectroscopy analysis on Rb x C 60 compounds with different stoichiometries (0-bar x-bar 6). Apart from shifts and broadening of the spectral features associated to the different phase formed, we observe in the RbC 60 phase the presence of the highest occupied molecular orbital (HOMO) shoulder and of its symmetric (with respect to the Fermi level) empty state. According to calculations, the metallicity of this phase and the presence of these electronic states may be taken as a fingerprint of the interplay between electron-electron and electron-phonon interactions in determining the electronic behavior of alkali metal fullerides

  9. Fullerene C60 and graphene photosensibiles for photodynamic virus inactivation

    Science.gov (United States)

    Belousova, I.; Hvorostovsky, A.; Kiselev, V.; Zarubaev, V.; Kiselev, O.; Piotrovsky, L.; Anfimov, P.; Krisko, T.; Muraviova, T.; Rylkov, V.; Starodubzev, A.; Sirotkin, A.; Grishkanich, A.; Kudashev, I.; Kancer, A.; Kustikova, M.; Bykovskaya, E.; Mayurova, A.; Stupnikov, A.; Ruzankina, J.; Afanasyev, M.; Lukyanov, N.; Redka, D.; Paklinov, N.

    2018-02-01

    A solid-phase photosensitizer based on aggregated C60 fullerene and graphene oxide for photodynamic inactivation of pathogens in biological fluids was studied. The most promising technologies of inactivation include the photodynamic effect, which consists in the inactivation of infectious agents by active oxygen forms (including singlet oxygen), formed when light is activated by the photosensitizer introduced into the plasma. Research shows features of solid-phase systems based on graphene and fullerene C60 oxide, which is a combination of an effective inactivating pathogens (for example, influenza viruses) reactive oxygen species formed upon irradiation of the photosensitizer in aqueous and biological fluids, a high photostability fullerene coatings and the possibility of full recovery photosensitizer from the biological environment after the photodynamic action.

  10. Local Segmental Dynamics and Stresses in Polystyrene - C$_{60}$ Mixtures

    OpenAIRE

    Vogiatzis, Georgios G.; Theodorou, Doros N.

    2014-01-01

    The polymer dynamics of homogeneous C$_{60}$-polystyrene mixtures in the molten state are studied via molecular simulations using two interconnected levels of representation for polystyrene nanocomposites: (a) A coarse-grained representation, in which each polystyrene repeat unit is mapped into a single "superatom" and each fullerene is viewed as a spherical shell. Equilibration of coarse-grained polymer-nanoparticle systems at all length scales is achieved via connectivity-altering Monte Car...

  11. La estructura del fullereno C60 y sus aplicaciones

    OpenAIRE

    Vasilievna Kharissova, Oxana; Ortiz Méndez, Ubaldo

    2002-01-01

    Se revisan los datos reportados de una nueva clase de materiales basados en los fullerenos. Se explica la estructura del fullereno C60 y sus compuestos con metales alcalinos, sus propiedades y aplicaciones. Se señala que estos compuestos tienen propiedades de superconducción comparable con la de los tradicionales cupratos. Se indica que esta modificación del carbono puede formar nanotubos que tienen varias aplicaciones prácticas debido a sus propiedades.

  12. Strong spin-filtering and spin-valve effects in a molecular V–C60–V contact

    Directory of Open Access Journals (Sweden)

    Mohammad Koleini

    2012-08-01

    Full Text Available Motivated by the recent achievements in the manipulation of C60 molecules in STM experiments, we study theoretically the structure and electronic properties of a C60 molecule in an STM tunneljunction with a magnetic tip and magnetic adatom on a Cu(111 surface using first-principles calculations. For the case of a vanadium tip/adatom, we demonstrate how spin coupling between the magnetic V atoms, mediated by the C60, can be observed in the electronic transport, which display a strong spin-filtering effect, allowing mainly majority-spin electrons to pass (>95%. Moreover, we find a significant change in the conductance between parallel and anti-parallel spin polarizations in the junction (86% which suggests that STM experiments should be able to characterize the magnetism and spin coupling for these systems.

  13. Strong spin-filtering and spin-valve effects in a molecular V-C-60-V contact

    DEFF Research Database (Denmark)

    Koleini, Mohammad; Brandbyge, Mads

    2012-01-01

    Motivated by the recent achievements in the manipulation of C-60 molecules in STM experiments, we study theoretically the structure and electronic properties of a C-60 molecule in an STM tunneljunction with a magnetic tip and magnetic adatom on a Cu(111) surface using first-principles calculations....... For the case of a vanadium tip/adatom, we demonstrate how spin coupling between the magnetic V atoms, mediated by the C-60, can be observed in the electronic transport, which display a strong spin-filtering effect, allowing mainly majority-spin electrons to pass (>95%). Moreover, we find a significant change...... in the conductance between parallel and anti-parallel spin polarizations in the junction (86%) which suggests that STM experiments should be able to characterize the magnetism and spin coupling for these systems....

  14. Asymmetric fission and evaporation of C60r+ (r = 2-4) fullerene ions in ion-C60 collisions: I. Proton results

    International Nuclear Information System (INIS)

    Rentenier, A; Bordenave-Montesquieu, A; Moretto-Capelle, P; Bordenave-Montesquieu, D

    2004-01-01

    A quantitative description of the asymmetric fission (AF) of C 60 r+ fullerene ions (r = 2-4), using a multistop coincidence technique between both fragment ions, is presented. Charged light fragment (LF) and heavy fragment (HF) size distributions are discussed together with the corresponding averaged sizes. Complete AF distributions are reported for the first time for C 60 2+ ions. Simple dependences of the more probable channels and averaged fragment sizes on the partner size are found and discussed. The LF ones are not very sensitive to the parent fullerene ion charge r and vary linearly with the HF size at least for the largest ones. On the other hand the HF ones present an oscillating dependence against the LF size, the odd-numbered LFs being correlated to a smaller HF size, and depend on r. In the comparison of branching ratios between AF and the competing pure neutral evaporation channel, some emphasis is given to the behaviour of the unimolecular processes with r which are compared with the evolution of the activation energies and fission barriers. From a close examination of the individual HF distributions the production mechanisms of odd-n fragments are discussed, and the most probable dissociation channels of even-numbered C n + excited carbon clusters identified. Finally, an analysis of the neutral channels is also presented for the first time, the total neutral mass N (in carbon units) being deduced from the mass conservation law. Surprising similarities between the charged LF- and N-distributions are found. AF processes are also identified where light neutrals and ions play a symmetrical role. These findings lead us to suggest that a concerted emission of ions and heavy neutrals is probably a fission mechanism to be considered to understand the AF process of the C 60 molecule in addition to the often assumed multistep fragmentation cascade scheme

  15. Aggregate development in C 60/N-methyl-2-pyrrolidone solution and its mixture with water as revealed by extraction and mass spectroscopy

    Science.gov (United States)

    Kyzyma, O. A.; Korobov, M. V.; Avdeev, M. V.; Garamus, V. M.; Snegir, S. V.; Petrenko, V. I.; Aksenov, V. L.; Bulavin, L. A.

    2010-06-01

    The aggregate development in C 60/N-methyl-2-pyrrolidone (C 60/NMP) solution with time is studied by the extraction (hexane) and mass spectroscopy. It is shown that only molecular C 60 in NMP is extracted in hexane, which makes it possible to follow a change in the concentration of non-aggregated fullerene in C 60/NMP during the aggregate growth. It is concluded that almost all fullerene dissolved in NMP is in the aggregates after one month. The reorganization of the aggregates is detected when water is added to the aggregated solution C 60/NMP. Both methods prove that in this case individual fullerene molecules are detached from the aggregates, which contradicts somewhat to complete insolubility of C 60 in water.

  16. Electronic Correlations, Jahn-Teller Distortions and Mott Transition to Superconductivity in Alkali-C60 Compounds

    Directory of Open Access Journals (Sweden)

    Alloul H.

    2012-03-01

    Full Text Available The discovery in 1991 of high temperature superconductivity (SC in A3C60 compounds, where A is an alkali ion, has been rapidly ascribed to a BCS mechanism, in which the pairing is mediated by on ball optical phonon modes. While this has lead to consider that electronic correlations were not important in these compounds, further studies of various AnC60 with n=1, 2, 4 allowed to evidence that their electronic properties cannot be explained by a simple progressive band filling of the C60 six-fold degenerate t1u molecular level. This could only be ascribed to the simultaneous influence of electron correlations and Jahn-Teller Distortions (JTD of the C60 ball, which energetically favour evenly charged C60 molecules. This is underlined by the recent discovery of two expanded fulleride Cs3C60 isomeric phases which are Mott insulators at ambient pressure. Both phases undergo a pressure induced first order Mott transition to SC with a (p, T phase diagram displaying a dome shaped SC, a common situation encountered nowadays in correlated electron systems. NMR experiments allowed us to study the magnetic properties of the Mott phases and to evidence clear deviations from BCS expectations near the Mott transition. So, although SC involves an electron-phonon mechanism, the incidence of electron correlations has an importance on the electronic properties, as had been anticipated from DMFT calculations.

  17. Photoionization of bonding and antibonding-type atom-fullerene hybrid states in Cd@C60 vs Zn@C60

    International Nuclear Information System (INIS)

    Javani, Mohammad H; Manson, Steven T; De, Ruma; Chakraborty, Himadri S; Madjet, Mohamed E

    2014-01-01

    Powerful hybridization of the Cd 4d state with the d-angular momentum state of C 60 π symmetry is found in the local density approximation (LDA) structure of Cd@C 60 ground state. The photoionization of the resulting symmetric and antisymmetric levels are computed using the time dependent LDA method to include electron correlations. Cross sections exhibit effects of the C 60 plasmonic motion coherently coupled to the diffraction-type cavity oscillations induced by local emissions from C 60 . The Cd@C 60 results exhibit a substantial difference from our previous results for Zn@C 60 . (paper)

  18. Insights into the stability and thermal degradation of P3HT:C60 blended films for solar cell applications

    CSIR Research Space (South Africa)

    Motaung, DE

    2011-03-01

    Full Text Available This paper demonstrates the changes in the nanoscale morphology of the blended films induced by a diffusion of C60 molecules and degradation during longer thermal treatment above the glass transition temperature (130 °C). The results showed...

  19. Physical properties of superconducting and ferromagnetic materials based on C60

    International Nuclear Information System (INIS)

    Thompson, J.D.; Sparn, G.; Diederich, F.; Gruener, G.; Holczer, K.; Kaner, R.B.; Whetten, R.L.; Allemand, P.M.; Chen, Q.; Wudl, F.

    1991-01-01

    We present results of magnetization and pressure measurements on recently discovered superconductors K 3 C 60 and Rb 3 C 60 , as well as ferromagnetic C 60 TDAE, and discuss the nature of the ground state suggested by these studies

  20. Quadrupole photoionization of endohedral Xe-C60

    International Nuclear Information System (INIS)

    Govil, Karan; Deshmukh, P C

    2009-01-01

    The effect of an endohedral confinement on the quadrupole photoionization of atomic Xe is studied using the relativistic random phase approximation (RRPA). The atom's confinement is modelled by placing atomic Xe at the centre of a C 60 cage represented by an annular potential around it. A new confinement resonance is reported in the 4p quadrupole cross-section along with 'correlation confinement resonances' in 4d, 5s and 5p photoionizations at about 185 eV. The effect of the confinement on the non-dipole photoelectron angular distribution parameter γ is also reported.

  1. Impact of Ultrathin C60 on Perovskite Photovoltaic Devices.

    Science.gov (United States)

    Liu, Dianyi; Wang, Qiong; Traverse, Christopher J; Yang, Chenchen; Young, Margaret; Kuttipillai, Padmanaban S; Lunt, Sophia Y; Hamann, Thomas W; Lunt, Richard R

    2018-01-23

    Halide perovskite solar cells have seen dramatic progress in performance over the past several years. Certified efficiencies of inverted structure (p-i-n) devices have now exceeded 20%. In these p-i-n devices, fullerene compounds are the most popular electron-transfer materials. However, the full function of fullerenes in perovskite solar cells is still under investigation, and the mechanism of photocurrent hysteresis suppression by fullerene remains unclear. In previous reports, thick fullerene layers (>20 nm) were necessary to fully cover the perovskite film surface to make good contact with perovskite film and avoid large leakage currents. In addition, the solution-processed fullerene layer has been broadly thought to infiltrate into the perovskite film to passivate traps on grain boundary surfaces, causing suppressed photocurrent hysteresis. In this work, we demonstrate an efficient perovskite photovoltaic device with only 1 nm C 60 deposited by vapor deposition as the electron-selective material. Utilizing a combination of fluorescence microscopy and impedance spectroscopy, we show that the ultrathin C 60 predominately acts to extract electrons from the perovskite film while concomitantly suppressing the photocurrent hysteresis by reducing space charge accumulation at the interface. This work ultimately helps to clarify the dominant role of fullerenes in perovskite solar cells while simplifying perovskite solar cell design to reduce manufacturing costs.

  2. Beam pulsing of C60 electrostatic injector accelerator for linac

    International Nuclear Information System (INIS)

    Takahashi, Y.; Hattori, T.; Kashiwagi, H.; Hata, T.; Noda, K.

    2000-01-01

    The research which measured the energy loss by the interaction between C 60 fullerene beam and solid film using the TOF method was started. The beam pulsing equipment was manufactured in this reason. The method by the copping was adopted for the pulsing, and 10 kHz high frequency was applied between electrodes, and the 20 V maximum voltage between electrodes was obtained. The 600 keV acceleration will be carried out by the 200 kV accelerating column, after pulsing is sent to C 60 fullerene beam drawn from electron impact type ion source at 300 V in pulse intervals 50 μs and 4.6 μs pulse width. The APF-IH type linear accelerator that it settles the fullerene more and more using the APF focusing and accelerates at the high acceleration is designed and is manufactured, and this is made to be a linear accelerator of back step, the high energy acceleration will be carried out. (author)

  3. Synthesis of mesogenic phthalocyanine-C60 donor–acceptor dyads designed for molecular heterojunction photovoltaic devices

    Directory of Open Access Journals (Sweden)

    Yves Henri Geerts

    2009-10-01

    Full Text Available A series of phthalocyanine-C60 dyads 2a–d was synthesized. Key steps in their synthesis are preparation of the low symmetry phthalocyanine intermediate by the statistical condensation of two phthalonitriles, and the final esterification of the fullerene derivative bearing a free COOH group. Structural characterization of the molecules in solution was performed by NMR spectroscopy, UV–vis spectroscopy and cyclic voltammetry. Preliminary studies suggest formation of liquid crystalline (LC mesophases for some of the prepared dyads. To the best of our knowledge, this is the first example of LC phthalocyanine-C60 dyads.

  4. Continuum modeling investigation of gigahertz oscillators based on a C60 fullerene inside cyclic peptide nanotubes

    Science.gov (United States)

    Sadeghi, F.; Ansari, R.; Darvizeh, M.

    2016-02-01

    Research concerning the fabrication of nano-oscillators with operating frequency in the gigahertz (GHz) range has become a focal point in recent years. In this paper, a new type of GHz oscillators is introduced based on a C60 fullerene inside a cyclic peptide nanotube (CPN). To study the dynamic behavior of such nano-oscillators, using the continuum approximation in conjunction with the 6-12 Lennard-Jones (LJ) potential function, analytical expressions are derived to determine the van der Waals (vdW) potential energy and interaction force between the two interacting molecules. Employing Newton's second law, the equation of motion is solved numerically to arrive at the telescopic oscillatory motion of a C60 fullerene inside CPNs. It is shown that the fullerene molecule exhibits different kinds of oscillation inside peptide nanotubes which are sensitive to the system parameters. Furthermore, for the precise evaluation of the oscillation frequency, a novel semi-analytical expression is proposed based on the conservation of the mechanical energy principle. Numerical results are presented to comprehensively study the effects of the number of peptide units and initial conditions (initial separation distance and velocity) on the oscillatory behavior of C60 -CPN oscillators. It is found out that for peptide nanotubes comprised of one unit, the maximum achievable frequency is obtained when the inner core oscillates with respect to its preferred positions located outside the tube, while for other numbers of peptide units, such frequency is obtained when the inner core oscillates with respect to the preferred positions situated in the space between the two first or the two last units. It is further found out that four peptide units are sufficient to obtain the optimal frequency.

  5. Perspective: C60+ and laboratory spectroscopy related to diffuse interstellar bands

    Science.gov (United States)

    Campbell, E. K.; Maier, J. P.

    2017-04-01

    In the last 30 years, our research has focused on laboratory measurements of the electronic spectra of organic radicals and ions. Many of the species investigated were selected based on their potential astrophysical relevance, particularly in connection with the identification of appealing candidate molecules for the diffuse interstellar absorptions. Notably, carbon chains and derivatives containing hydrogen and nitrogen atoms in their neutral and ionic forms were studied. These data could be obtained after developing appropriate techniques to record spectra at low temperatures relevant to the interstellar medium. The measurement of gas phase laboratory spectra has enabled direct comparisons with astronomical data to be made and though many species were found to have electronic transitions in the visible where the majority of diffuse bands are observed, none of the absorptions matched the prominent interstellar features. In 2015, however, the first carrier molecule was identified: C60 + . This was achieved after the measurement of the electronic spectrum of C60 + -He at 6K in a radiofrequency ion trap.

  6. Growth of nanocomposite films from accelerated C60 ions

    International Nuclear Information System (INIS)

    Pukha, V E; Zubarev, E N; Drozdov, A N; Pugachov, A T; Jeong, S H; Nam, S C

    2012-01-01

    A beam of accelerated C 60 ions is used to deposit superhard (∼50 GPa) carbon films that exhibit high index plasticity (∼0.13-0.14) and high conductivity (up to 3000 S m -1 ). Transmission electron microscopy, Raman spectroscopy and x-ray photoelectron spectroscopy are subsequently used to study the microstructure and bond character of the deposited films. The films consist of textured graphite nanocrystals and diamond-like amorphous carbon (DLC). The graphene plane of the nanocrystals is aligned perpendicular to the film surface. It is shown that sp 2 bonds dominate in the films. The percentage of sp 3 bonds depends on the ion energy and the substrate temperature, and does not exceed 40%. The obtained results suggest that a new nanocomposite material consisting of oriented graphite nanocrystals reinforced by a DLC matrix is synthesized. A simple model is proposed to correlate the excellent mechanical properties with the observed structure. (paper)

  7. Potential dependence of the effective attraction in doped C60

    International Nuclear Information System (INIS)

    Goff, W.E.; Phillips, P.

    1992-01-01

    In an effort to explain superconductivity in the alkali-doped C 60 , Chakravarty and Kivelson have proposed that there is a net effective electron attraction due to intramolecular Coulomb forces. The calculation makes use of a Hubbard model in which long-range interactions are absent. The authors show that this result strongly depends on the form of the electron-electron interaction and that for potentials with long-range interactions, e.g. an Ohno potential that interpolates between an on site energy and 1/r at large distances, they do not find an effective attraction. Reasonable screening does not significantly modify this result. This indicates that the electronic mechanism in the proposed form cannot be the primary source of an attractive interaction

  8. Empirical tight-binding parameters for solid C60

    International Nuclear Information System (INIS)

    Tit, N.; Kumar, V.

    1993-01-01

    We present a tight-binding model for the electronic structure of C 60 using four (1s and 3p) orbitals per carbon atom. The model has been developed by fitting the tight-binding parameters to the ab-initio pseudopotential calculation of Troullier and Martins (Phys. Rev. B46, 1754 (1992)) in the face-centered cubic (Fm3-bar) phase. Following this, calculations of the energy bands and the density of electronic states have been carried out as a function of the lattice constant. Good agreement has been obtained with the observed lattice-constant dependence of T c using McMillan's formula. Furthermore, calculations of the electronic structure are presented in the simple cubic (Pa3-bar) phase. (author). 43 refs, 3 figs, 1 tab

  9. On interface dipole layers between C60 and Ag or Au

    NARCIS (Netherlands)

    Veenstra, Sjoerd; Heeres, A.; Hadziioannou, G.; Sawatzky, G.A.; Jonkman, H.T.

    2002-01-01

    C60 layers on polycrystalline Ag and Au are studied by photoelectron spectroscopy. At these metal/C60 interfaces an electron transfer occurs from the metal to the lowest unoccupied orbital of C60. We found in the case of the polycrystalline Ag/C60 interface a dipolar layer with its associated

  10. Topological edge properties of C60+12n fullerenes

    Directory of Open Access Journals (Sweden)

    A. Mottaghi

    2013-06-01

    Full Text Available A molecular graph M is a simple graph in which atoms and chemical bonds are the vertices and edges of M, respectively. The molecular graph M is called a fullerene graph, if M is the molecular graph of a fullerene molecule. It is well-known that such molecules exist for even integers n ≥ 24 or n = 20. The aim of this paper is to investigate the topological properties of a class of fullerene molecules containing 60 + 12n carbon atoms.

  11. New Identifications of the CCH Radical in Planetary Nebulae: A Connection to C60?

    Science.gov (United States)

    Schmidt, D. R.; Ziurys, L. M.

    2017-12-01

    New detections of CCH have been made toward nine planetary nebulae (PNe), including K4-47, K3-58, K3-17, M3-28, and M4-14. Measurements of the N = 1 → 0 and N = 3 → 2 transitions of this radical near 87 and 262 GHz were carried out using the new 12 m and the Sub-Millimeter Telescope (SMT) of the Arizona Radio Observatory (ARO). The presence of fine and/or hyperfine structure in the spectra aided in the identification. CCH was not observed in two PNe which are sources of C60. The planetary nebulae with positive detections represent a wide range of ages and morphologies, and all had previously been observed in HCN and HNC. Column densities for CCH in the PNe, determined from radiative transfer modeling, were N tot(CCH) ˜ 0.2-3.3 × 1015 cm-2, corresponding to fractional abundances with respect to H2 of f ˜ 0.2-47 × 10-7. The abundance of CCH was found to not vary significantly with kinematic age across a time span of ˜10,000 years, in contrast to predictions of chemical models. CCH appears to be a fairly common constituent of PNe that are carbon-rich, and its distribution may anti-correlate with that of C60. These results suggest that CCH may be a product of C60 photodestruction, which is known to create C2 units. The molecule may subsequently survive the PN stage and populate diffuse clouds. The distinct, double-horned line profiles for CCH observed in K3-45 and M3-28 indicate the possible presence of a bipolar flow oriented at least partially toward the line of sight.

  12. C60 ion sputtering of layered organic materials

    International Nuclear Information System (INIS)

    Shard, Alexander G.; Green, Felicia M.; Gilmore, Ian S.

    2008-01-01

    Two different organic materials, Irganox1010 and Irganox3114, were vacuum deposited as alternating layers. The layers of Irganox3114 were thin (∼2.5 nm) in comparison to the Irganox1010 (∼55 or ∼90 nm); we call these 'organic delta layers'. Both materials are shown to have identical sputtering yields and the alternating layers may be used to determine some of the important metrological parameters for cluster ion beam depth profiling of organic materials. The sputtering yield for C 60 ions is shown to diminish with ion dose. Comparison with atomic force microscopy data from films of pure Irganox1010, demonstrates that the depth resolution is limited by the development of topography. Secondary ion intensities are a well-behaved function of sputtering yield and may be employed to obtain useful analytical information. Organic delta layers are shown to be valuable reference materials for comparing the capabilities of different cluster ion sources and experimental arrangements for the depth profiling of organic materials.

  13. a.c. conductance study of polycrystal C60

    International Nuclear Information System (INIS)

    Yan Feng; Wang Yening; Huang Yineng; Gu Min; Zhang Qingming; Shen Huimin

    1995-01-01

    The a.c. (1 60 polycrystal (grain size 30 nm) has been studied from 100 to 350 K. Below 150 K, the a.c. conductance is nearly proportional to the temperature and frequency. This is proposed to be due to the hopping of localized states around the Fermi level. Above 200 K, the a.c. conductance exhibits a rapid increase with temperature, and shows a thermally activated behaviour with an activation energy of 0.389 eV below a certain temperature and 0.104 eV above it. A frequency dependent conductance at a fixed temperature is also obtained with a power law σ similar ω s (s∼0.8). For a sample of normal grain size, we have measured a peak near 250 K and a much smaller conductance. These results indicate that the defective na ture of our sample (small grain size, disorder or impurities) plays an important role for the transport properties. The existence of nanocrystals in the sample may give rise to localized states and improve its a.c. conductance. The two activation energies can be attributed to the coexistence of the crystalline and amorphous phases of C 60 . ((orig.))

  14. Growth and FIB-SEM analyses of C60 microtubes vertically synthesized on porous alumina membranes

    Science.gov (United States)

    Miyazawa, Kun'ichi; Kuriyama, Ryota; Shimomura, Shuichi; Wakahara, Takatsugu; Tachibana, Masaru

    2014-02-01

    The vertical growth of C60 microtubes (C60MTs) on anodic aluminum oxide (AAO) membranes was investigated. The C60MT size dependence on isopropyl alcohol (IPA) injection rate, into C60-saturated toluene solutions through AAO membranes, was measured. A longitudinal section of the interface between a vertically grown C60MT (V-C60MT) and a membrane was prepared by focused ion beam processing, and observed with scanning electron microscopy. No cracking was observed along the interface, suggesting good bonding. V-C60MTs exhibited spiral growth. V-C60MT planar density, wall thickness and aspect ratio all decreased with increasing IPA injection rate. The relationships among length, inner and outer diameters of V-C60MTs were also investigated by varying IPA injection rate.

  15. Study of Flux Ratio of C60 to Ar Cluster Ion for Hard DLC Film deposition

    International Nuclear Information System (INIS)

    Miyauchi, K.; Toyoda, N.; Kanda, K.; Matsui, S.; Kitagawa, T.; Yamada, I.

    2003-01-01

    To study the influence of the flux ratio of C60 molecule to Ar cluster ion on (diamond like carbon) DLC film characteristics, DLC films deposited under various flux ratios were characterized with Raman spectrometry and Near Edge X-ray Absorption Fine Structure (NEXAFS). From results of these measurements, hard DLC films were deposited when the flux ratio of C60 to Ar cluster ion was between 0.7 and 4. Furthermore the DLC film with constant sp2 content was obtained in the range of the ratio from 0.7 to 4, which contents are lower values than that of conventional films such as RF plasma. DLC films deposited under the ratio from 1 to 4 had hardness from 40 to 45GPa. It was shown that DLC films with stable properties of low sp2 content and high hardness were formed even when the fluxes were varied from 1 to 4 during deposition. It was indicated that this process was useful in the view of industrial application

  16. In-Silico Study Of Water Soluble C60-Fullerene Derivatives And Different Drug Targets

    Directory of Open Access Journals (Sweden)

    Mohammad Teimouri

    2015-08-01

    Full Text Available Fullerene C60 is a unique carbon molecule that adopts a sphere shape. It has been proved that fullerene and some of its derivatives several disease targets. Fullerene itself is insoluble in water. So fullerene application is hindered in medical field. In this study a literature search was performed and all derivatives were collected. The fullerene binding protein previously reported in literature were also retrieved from protein databank. The docking study were performed with fullerene derivatives and its binding proteins. The selected proteins include Voltage-Gated Potassium Channel estrogenic 17beta-hydroxysteroid dehydrogenase and monoclonal anti-progesterone antibody. The binding affinity and binding free energy were computed for these proteins and fullerene derivatives complexes. The binding affinity and binding free energy calculation of the co-crystal ligands were also carried out. The results show the good fitting of fullerene derivatives in the active site of different proteins. The binding affinities and binding free energies of fullerene derivatives are better. The present study gives a detail information about the binding mode of C60 derivatives. The finding will be helpful in fullerene-based drug discovery and facilitate the efforts of fighting many diseases.

  17. Parallel beam powder diffraction study on the A1C60 system (A=K, Rb)

    International Nuclear Information System (INIS)

    Faigel, G.; Tegze, M.; Bortel, G.; Forro, L.; Oszlanyi, G.; Stephens, P.W.

    1994-01-01

    We report x-ray powder diffraction studies on Rb x C 60 and K x C 60 . It is shown that at room temperature there exist stoichiometric compounds in the Rb x C 60 and K x C 60 systems at the x = 1 composition. Their equilibrium structures are pseudo body centered orthorhombic. The C 60 -C 60 intermolecular separation (9.1 A) is the shortest among the known alkali-fullerides. A first order phase transition is observed at about 380 K from the high temperature fcc phase to the room temperature orthorhombic phase. (orig.)

  18. Crystal and molecular structure of new fullerides (Ph4P)2C60Hal (Hal = Br, I) and (Ph4As)2C60Cl

    International Nuclear Information System (INIS)

    Gritsenko, V.V.; D'yachenko, O.A.; Shilov, G.V.; Spitsyn, N.G.; Yagubskij, E h.B.

    1997-01-01

    New stable on air fullerides (Ph 4 P) 2 C 60 Hal (Hal = Br, I) and (Ph 4 As) 2 C 60 Cl were synthesized and their crystal structure were determined. On the basis of their relative crystallochemical analysis fullerides obtained were shown to be isostructural. They are described by general formula (Ph 4 X) 2 C 60 Hal (X = H, As; Hal = Cl, Br, I) and crystallized in triclinic system. Anions C 60 - and Hal - occupy the centre-symmetrical positions, cations (PH 4 P) + and (Ph 4 As) + occupy the general positions. The main parameters of molecular structure are presented

  19. Bioapplication and activity of fullerenol C 60 (OH) | Rade | African ...

    African Journals Online (AJOL)

    In addition, several derivatives have shown immunomodulating, neuroprotective and radioprotective effect. Fullerenes are hydrophobic molecules best dissolved in organic solvents, so potential biomedical applications are restricted by their extremely poor solubility in polar solvents. One of the strategies for improving poor ...

  20. The effect of water on the stability of C60 fullerene nanowhiskers

    International Nuclear Information System (INIS)

    Miyazawa, Kun’ichi; Hotta, Kayoko

    2011-01-01

    The morphology of C 60 precipitates synthesized by using isopropyl alcohol (IPA) added with water was investigated in order to know the effect of water on the growth of C 60 nanowhiskers (C 60 NWs) in C 60 –toluene–IPA solution systems. The stability of C 60 NWs decreased and granular crystals of C 60 were formed in the solutions when IPA added with an excess amount of water was used in the liquid–liquid interfacial precipitation method. The C 60 NWs were found to be destabilized with time in the solutions added with water. The C 60 NWs dried in air showed similar Raman profiles irrespective of the use of IPA with and without water addition. The Raman profiles of granular C 60 single crystals showed the base lines much flatter than those of C 60 NWs, indicating that C 60 NWs possess a disordered crystal structure. By optimizing the growth condition, short C 60 NWs with aspect ratios ranging from 3 to 10 and an average length of about 1.8 μm were successfully fabricated. The short C 60 NWs are expected to be applicable for electrodes of organic thick film solar cells.

  1. Entire Agreement Clauses

    DEFF Research Database (Denmark)

    Mitkidis, Katerina; Neumann, Thomas

    2017-01-01

    , it can then be expected that the contract drafting practice will in turn influence national legal rules and the courts’ approach. This effect can already be seen in Danish legal scholarship and its presumption that the judges will not entirely disregard EA clauses, but take a middle road in interpreting......, but also the contract drafting style typical for common law countries. In this way, common law concepts and rules can be transferred to civil law jurisdictions, however, without certainty about the legal effects. This is especially pertinent to boilerplate provisions. On this background, the article aims...

  2. Spectra of elementary excitations of fullerenes C60 and electron irradiation effect

    International Nuclear Information System (INIS)

    Gordeev, Yu.S.; Mikushkin, V.M.; Shnitov, V.V.

    2000-01-01

    The electron-stimulated changes in the spectra of the fullerenes C 60 elementary excitations are determined. They are manifested in decreasing the π-plasmon energy, the forbidden zone width, the HOMO-LUMO transition energy and also in smoothing the corresponding peculiarities of the spectra. The observed red shifts are connected with collectivization of the part of the π-electrons, formation of chemically-bound neighbouring molecules (polymerization) and with the corresponding increase in the part of the sp 3 -hybridized electrons. The spectra of the characteristic energy losses of the fullerene electrons, unperturbed by the polymerization process, are measured. The multipole structure of the (σ + π) plasmon and the exciton peculiarity, which manifests high sensitivity to the electron impact and may be used for the fullerene initial structure characterization, is identified [ru

  3. Nano-Saturn: Experimental Evidence of Complex Formation of an Anthracene Cyclic Ring with C60.

    Science.gov (United States)

    Yamamoto, Yuta; Tsurumaki, Eiji; Wakamatsu, Kan; Toyota, Shinji

    2018-05-30

    An anthracene cyclic hexamer was synthesized by the coupling reaction as a macrocyclic hydrocarbon host. This disk-shaped host included a C 60 guest in 1:1 ratio to form a Saturn-type supramolecular complex in solution and in crystals. X-ray analysis unambiguously revealed that the guest molecule was accommodated in the middle of the host cavity with several CH⋅⋅⋅π contacts. The association constant K a determined by NMR titration measurements was 2.3×10 3  L mol -1 at 298 K in toluene. The structural features and the role of CH⋅⋅⋅π interactions are discussed with the aid of DFT calculations. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Quantum fluctuations of D5d polarons on C60 molecules

    International Nuclear Information System (INIS)

    Wang Chui-Lin; Wang Wenzheng; Liu Yuliang; Su Zhaobin; Yu Lu.

    1994-06-01

    The dynamic Jahn-Teller splitting of the six equivalent D 5d polarons due to quantum fluctuations is studied in the framework of the Bogoliubov-de Gennes formalism. The tunneling induced level splittings are determined to be 2 T 1u + 2 T 2u and 1 A g + 1 H g for C 1- 60 and C -2 60 , respectively, which should give rise to observable effects in experiments. (author). 17 refs, 2 tabs

  5. Effects of C60 nanoparticle exposure on earthworms (Lumbricus rubellus) and implications for population dynamics

    International Nuclear Information System (INIS)

    Ploeg, M.J.C. van der; Baveco, J.M.; Hout, A. van der; Bakker, R.; Rietjens, I.M.C.M.; Brink, N.W. van den

    2011-01-01

    Effects of C 60 nanoparticles (nominal concentrations 0, 15.4 and 154 mg/kg soil) on mortality, growth and reproduction of Lumbricus rubellus earthworms were assessed. C 60 exposure had a significant effect on cocoon production, juvenile growth rate and mortality. These endpoints were used to model effects on the population level. This demonstrated reduced population growth rate with increasing C 60 concentrations. Furthermore, a shift in stage structure was shown for C 60 exposed populations, i.e. a larger proportion of juveniles. This result implies that the lower juvenile growth rate due to exposure to C 60 resulted in a larger proportion of juveniles, despite increased mortality among juveniles. Overall, this study indicates that C 60 exposure may seriously affect earthworm populations. Furthermore, it was demonstrated that juveniles were more sensitive to C 60 exposure than adults. - C 60 nanoparticle exposure can affect Lumbricus rubellus populations.

  6. In the search of an electron transfer between π-donors and C60: the bis-linking of tetrathiafulvalene (TTF) to C60

    International Nuclear Information System (INIS)

    Hudhomme, P.; Rabreau, J.M.; Cariou, M.; Jubault, M.; Gorgues, A.

    1998-01-01

    In order to realize the bis-linking of tetrathiafulvalene (TTF) to one or two C 60 , and to reach the dyad compounds 1 and 2, the [4+2] Diels-Alder reactions of C 60 with orthoquinodimethanic derivatives of 1,3-dithioles 5a,b or TTF 9 are studied. (orig.)

  7. Electronic transitions and band offsets in C60:SubPc and C60:MgPc on MoO3 studied by modulated surface photovoltage spectroscopy

    International Nuclear Information System (INIS)

    Fengler, S.; Dittrich, Th.; Rusu, M.

    2015-01-01

    Electronic transitions at interfaces between MoO 3 layers and organic layers of C 60 , SubPc, MgPc, and nano-composite layers of SubPc:C 60 and MgPc:C 60 have been studied by modulated surface photovoltage (SPV) spectroscopy. For all systems, time dependent and modulated SPV signals pointed to dissociation of excitons at the MoO 3 /organic layer interfaces with a separation of holes towards MoO 3 . The highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gaps (E HL ) of C 60 , SubPc, and MgPc and the effective E HL of SubPc:C 60 and MgPc:C 60 were measured. The offsets between the LUMO (ΔE L ) or HOMO (ΔE H ) bands were obtained with high precision and amounted to 0.33 or 0.73 eV for SubPc:C 60 , respectively, and to −0.33 or 0.67 eV for MgPc:C 60 , respectively. Exponential tails below E HL and most pronounced sub-bandgap transitions were characterized and ascribed to disorder and transitions from HOMO bands to unoccupied defect states

  8. Electron transfer and energy transfer reactions in photoexcited a-nonathiophene/C60 films and solutions

    NARCIS (Netherlands)

    Janssen, R.A.J.; Moses, D.; Sariciftci, N.S.; Heeger, A.J.

    1994-01-01

    Photoexcitation of a nonathiophene in film or solution across the p-p* energy gap produces a metastable triplet state. In the presence of C60, on the other hand, an ultra fast electron transfer from the photoexcited nonathiophene onto C60 is observed in films, whereas in solution C60 is involved in

  9. Molecular immune recognition of botulinum neurotoxin B. The light chain regions that bind human blocking antibodies from toxin-treated cervical dystonia patients. Antigenic structure of the entire BoNT/B molecule.

    Science.gov (United States)

    Atassi, M Zouhair; Jankovic, Joseph; Steward, Lance E; Aoki, K Roger; Dolimbek, Behzod Z

    2012-01-01

    We recently mapped the regions on the heavy (H) chain of botulinum neurotoxin, type B (BoNT/B) recognized by blocking antibodies (Abs) from cervical dystonia (CD) patients who develop immunoresistance during toxin treatment. Since blocking could also be effected by Abs directed against regions on the light (L) chain, we have mapped here the L chain, using the same 30 CD antisera. We synthesized, purified and characterized 32 19-residue L chain peptides that overlapped successively by 5 residues (peptide L32 overlapped with peptide N1 of the H chain by 12 residues). In a given patient, Abs against the L chain seemed less intense than those against H chain. Most sera recognized a limited set of L chain peptides. The levels of Abs against a given region varied with the patient, consistent with immune responses to each epitope being under separate MHC control. The peptides most frequently recognized were: L13, by 30 of 30 antisera (100%); L22, by 23 of 30 (76.67%); L19, by 15 of 30 (50.00%); L26, by 11 of 30 (36.70%); and L14, by 12 of 30 (40.00%). The activity of L14 probably derives from its overlap with L13. The levels of Ab binding decreased in the following order: L13 (residues 169-187), L22 (295-313), L19 (253-271), and L26 (351-369). Peptides L12 (155-173), L18 (239-257), L15 (197-215), L1 (1-19) and L23 (309-327) exhibited very low Ab binding. The remaining peptides had little or no Ab-binding activity. The antigenic regions are analyzed in terms of their three-dimensional locations and the enzyme active site. With the previous localization of the antigenic regions on the BoNT/B H chain, the human Ab recognition of the entire BoNT/B molecule is presented and compared to the recognition of BoNT/A by human blocking Abs. Copyright © 2011. Published by Elsevier GmbH.

  10. C60-Fullerenes: detection of intracellular photoluminescence and lack of cytotoxic effects

    Directory of Open Access Journals (Sweden)

    Carroll David L

    2006-12-01

    Full Text Available Abstract We have developed a new method of application of C60 to cultured cells that does not require water-solubilization techniques. Normal and malignant cells take-up C60 and the inherent photoluminescence of C60 is detected within multiple cell lines. Treatment of cells with up to 200 μg/ml (200 ppm of C60 does not alter morphology, cytoskeletal organization, cell cycle dynamics nor does it inhibit cell proliferation. Our work shows that pristine C60 is non-toxic to the cells, and suggests that fullerene-based nanocarriers may be used for biomedical applications.

  11. Effect of He pressure on the superconducting transition temperatures of Na2CsC60 and (NH3)4Na2CsC60

    International Nuclear Information System (INIS)

    Schirber, J.E.; Bayless, W.R.; Rosseinsky, M.J.; Zhou, O.; Fleming, R.M.; Murphy, D.; Fischer, J.E.

    1994-01-01

    The Na based mixed alkali doped C 60 superconductors show anomalous behavior with respect to the ''universal'' superconducting transition temperature T c vs lattice constant a 0 relation followed by most of the fcc A 3 C 60 superconductors. We have measured dt c /dP for Na 2 CsC 60 and (NH 3 ) 4 Na 2 CsC 60 using solid He as the pressure medium to ∼ 6 kbar finding dT c /dP equal to -0.8±(0.01) K/kbar and -1.0(±0.1)K/kbar for Na 2 CsC 60 and Na 2 (NH 3 ) 4 C 60 respectively. Our value for Na 2 CsC 60 differs markedly from that obtained by Mizuki et al of about -1.3 K/kbar. However, using N 2 or Ar, we obtain values for dT c /dP in substantial agreement with Mizuki et al who used fluorinert to generate their pressure. This work emphasizes the need for compressibility measurements with the same pressure medium in the appropriate temperature range so that meaningful comparisons can be made between various pressure measurements and models which are based on lattic spacing

  12. Study on the origin of pressure-induced superconductivity of Cs3C60

    International Nuclear Information System (INIS)

    Fujiki, S.; Kubozono, Y.; Takabayashi, Y.; Kashino, S.; Kobayashi, M.; Ishii, K.; Suematsu, H.

    2001-01-01

    Physical properties of bco phase of Cs 3+α C 60 (α=0.0-1.0) and A15 phase of Cs 3 C 60 are studied by X-ray diffraction, ESR, AC susceptibility, resistivity and Raman. The ESR of Cs 300(6) C 60 showed a broad peak of ∼380 G due to conduction electron, while no broad peak was observed in the ESR of bco Cs 3+α C 60 (α≠0.0) and A15 phase. This shows that only bco phase of Cs 3 C 60 is metallic. The AC susceptibility of bco phase of Cs 3.2(3) C 60 and Cs 3.5(1) C 60 showed no superconducting transition above 1.3 K even under high pressure, and the resistivity was 0.52 Ω cm for both samples

  13. Potential energy and dipole moment surfaces for HF@C60: Prediction of spectral and electric response properties

    Science.gov (United States)

    Kalugina, Yulia N.; Roy, Pierre-Nicholas

    2017-12-01

    We present a five-dimensional potential energy surface (PES) for the HF@C60 system computed at the DF-LMP2/cc-pVTZ level of theory. We also calculated a five-dimensional dipole moment surface (DMS) based on DFT(PBE0)/cc-pVTZ calculations. The HF and C60 molecules are considered rigid with bond length rHF = 0.9255 Å (gas phase ground rovibrational state geometry). The C60 geometry is of Ih symmetry. The ab initio points were fitted to obtain a PES in terms of bipolar spherical harmonics. The minimum of the PES corresponds to a geometry where the center of mass of HF is located 0.11 Å away from the center of the cage with an interaction energy of -6.929 kcal/mol. The DMS was also represented in terms of bipolar spherical harmonics. The PES was used to calculate the rotation-translation bound states of HF@C60, and good agreement was found relative to the available experimental data [A. Krachmalnicoff et al., Nat. Chem. 8, 953 (2016)] except for the splitting of the first rotational excitation levels. We propose an empirical adjustment to the PES in order to account for the experimentally observed symmetry breaking. The form of that effective PES is additive. We also propose an effective Hamiltonian with an adjusted rotational constant in order to quantitatively reproduce the experimental results including the splitting of the first rotational state. We use our models to compute the molecular volume polarizability of HF confined by C60 and obtain good agreement with experiment.

  14. In situ XRD study of C60 polymerisation above pressures of 9 GPa and temperatures up to 830K

    International Nuclear Information System (INIS)

    Talyzin, A.V.; Jansson, U.; Dubrovinsky, L.S.; Oden, M.; Le Bihan, T.

    2002-01-01

    The C60 polymerization was studied by X-ray diffraction in situ in the pressure range 13-18 GPa and at temperatures up to 830 K. The results of the high pressure high temperature treatment are strongly dependent from the history of the sample and stress. At certain conditions no elliptical diffraction patterns were observed at 13 GPa and 830K. Samples with a relatively low internal stress showed a transformation to new phase. It is suggested that this phase is three-dimensional polymer with each C60 molecule bonded to eight neighbors. This phase showed an increased hardness (about 37 GPa) and a Raman spectrum distinctly different from previously known polymeric phases

  15. The existence of a plastic phase and a solid-liquid dynamical bistability region in small fullerene cluster (C60)7: molecular dynamics simulation

    International Nuclear Information System (INIS)

    Piatek, A; Dawid, A; Gburski, Z

    2006-01-01

    We have simulated (by the molecular dymanics (MD) method) the dynamics of fullerenes (C 60 ) in an extremely small cluster composed of only as many as seven C 60 molecules. The interaction is taken to be the full 60-site pairwise additive Lennard-Jones (LJ) potential which generates both translational and anisotropic rotational motions of each molecule. Our atomically detailed MD simulations discover the plastic phase (no translations but active reorientations of fullerenes) at low energies (temperatures) of the (C 60 ) 7 cluster. We provide the in-depth evidence of the dynamical solid-liquid bistability region in the investigated cluster. Moreover, we confirm the existence of the liquid phase in (C 60 ) 7 , the finding of Gallego et al (1999 Phys. Rev. Lett. 83 5258) obtained earlier on the basis of Girifalco's model, which assumes single-site only and spherically symmetrical interaction between C 60 molecules. We have calculated the translational and angular velocity autocorrelation functions and estimated the diffusion coefficient of fullerene in the liquid phase

  16. Relativistic electronic structure calculations on endohedral Gd rate at C60, La rate at C60, Gd rate at C74, and La rate at C74

    International Nuclear Information System (INIS)

    Lu, J.; Zhang, X.; Zhao, X.

    2000-01-01

    Relativistic discrete-variational local density functional calculations on endohedral Gd rate at C 60 , La rate at C 60 ,Gd rate at C 74 , and La rate at C 74 are performed. All the C 60 - and C 74 -derived levels are lowered upon endohedral Gd and La doping. Both the Gd (4f 7 5d 1 6s 2 ) and La (5d 1 6s 2 ) atoms only donate their two 6s valence electrons to the cages, leaving behind their 5d electrons when they are placed at the cage centers. Compared with large-band-gap C 60 , small-band-gap C 74 and Gd (La)-metallofullerenes have strong both electron-donating and electron-accepting characters, and the calculated ionization potentials and electron affinities for them agree well with the available experimental data. (orig.)

  17. Largely enhanced thermal and mechanical properties of polymer nanocomposites via incorporating C60@graphene nanocarbon hybrid

    International Nuclear Information System (INIS)

    Song, Ping’an; Liu, Lina; Yu, Youming; Huang, Guobo; Guo, Qipeng

    2013-01-01

    Although considerable progress has been achieved to create advanced polymer nanocomposites using nanocarbons including fullerene (C 60 ) and graphene, it remains a major challenge to effectively disperse them in a polymer matrix and to fully exert their extraordinary properties. Here we report a novel approach to fabricate the C 60 @graphene nanocarbon hybrid (C 60 : ∼47.9 wt%, graphene: ∼35.1%) via three-step reactions. The presence of C 60 on a graphene sheet surface can effectively prevent the aggregation of the latter which in turn helps the dispersion of the former in a polymer matrix during melt-processing. C 60 @graphene is found to be uniformly dispersed in a polypropylene (PP) matrix. Compared with pristine C 60 or graphene, C 60 @graphene further improves the thermal stability and mechanical properties of PP. The incorporation of 2.0 wt% C 60 @graphene (relative to PP) can remarkably increase the initial degradation temperature by around 59 ° C and simultaneously enhance the tensile strength and Young’s modulus by 67% and 76%, respectively, all of which are higher than those of corresponding PP/C 60 (graphene) nanocomposites. These significant performance improvements are mainly due to the free-radical-trapping effect of C 60 , and the thermal barrier and reinforcing effects of graphene nanosheets as well as the effective stress load transfer. This work provides a new methodology to design multifunctional nanohybrids for creating advanced materials. (paper)

  18. Dispersion of C(60) in natural water and removal by conventional drinking water treatment processes.

    Science.gov (United States)

    Hyung, Hoon; Kim, Jae-Hong

    2009-05-01

    The first objective of this study is to examine the fate of C(60) under two disposal scenarios through which pristine C(60) is introduced to water containing natural organic matter (NOM). A method based on liquid-liquid extraction and HPLC to quantify nC(60) in water containing NOM was also developed. When pristine C(60) was added to water either in the form of dry C(60) or in organic solvent, it formed water stable aggregates with characteristics similar to nC(60) prepared by other methods reported in the literature. The second objective of this study is to examine the fate of the nC(60) in water treatment processes, which are the first line of defense against ingestion from potable water -- a potential route for direct human consumption. Results obtained from jar tests suggested that these colloidal aggregates of C(60) were efficiently removed by a series of alum coagulation, flocculation, sedimentation and filtration processes, while the efficiency of removal dependent on various parameters such as pH, alkalinity, NOM contents and coagulant dosage. Colloidal aggregates of functionalized C(60) could be well removed by the conventional water treatment processes but with lesser efficiency compared to those made of pristine C(60).

  19. Plasticization effect of C60 on the fast dynamics of polystyrene and related polymers: an incoherent neutron scattering study

    International Nuclear Information System (INIS)

    Sanz, Alejandro; Ruppel, Markus; Cabral, Joao T; Douglas, Jack F

    2008-01-01

    We utilize inelastic incoherent neutron scattering (INS) to quantify how fullerenes affect the 'fast' molecular dynamics of a family of polystyrene related macromolecules. In particular, we prepared bulk nanocomposites of (hydrogenous and ring-deuterated) polystyrene and poly(4-methyl styrene) using a rapid precipitation method where the C 60 relative mass fraction ranged from 0% to 4%. Elastic window scan measurements, using a high resolution (0.9 μeV) backscattering spectrometer, are reported over a wide temperature range (2-450 K). Apparent Debye-Waller (DW) factors 2 >, characterizing the mean-square amplitude of proton displacements, are determined as a function of temperature, T. We find that the addition of C 60 to these polymers leads to a progressive increase in 2 > relative to the pure polymer value over the entire temperature range investigated, where the effect is larger for larger nanoparticle concentration. This general trend seems to indicate that the C 60 nanoparticles plasticize the fast (∼10 -15 s) local (∼1 A) dynamics of these polymer glasses. Generally, we expect nanoparticle additives to affect polymer dynamics in a similar fashion to thin films in the sense that the high interfacial area may cause both a speeding up and slowing down of the glass state dynamics depending on the polymer-surface interaction

  20. Electron transfer and multi-ionization in slow collisions of C60 with highly charged ions

    International Nuclear Information System (INIS)

    Wei, B.; Ma, X.; Zhu, X.L.; Liu, H.P.; Wang, Z.L.; Sha, S.; Feng, W.T.; Cao, S.P.; Qian, D.B.; Li, B.; Chen, L.F.

    2005-01-01

    In the collisions of 20qkeV Ar q+ with C 60 , the relative cross-section for the production of higher charge of C 60 r+ increases with the initial charge state of the projectiles increasing. By comparing the TOF spectra produced by 56keV and 160keV Ar 8+ ion impact, respectively, we found that the intensity of the fragments C (60-2n) r+ via evaporation at higher energy was much less

  1. Electronic structure and static dipole polarizability of C60-C240

    International Nuclear Information System (INIS)

    Zope, Rajendra R

    2008-01-01

    The electronic structure of C 60 -C 240 and its first-order response to a static electric field is studied by an all-electron density functional theory calculation using large polarized Gaussian basis sets. Our results show that the outer C 240 shell almost completely shields the inner C 60 as inferred from the practically identical values of dipole polarizability of the C 60 -C 240 onion (449 A 3 ) and that of the isolated C 240 fullerene (441 A 3 ). The C 60 -C 240 is thus a near-perfect Faraday cage

  2. γ Radiolysis of C60 fullerene in water and water/ammonia mixtures: relevance of fullerene fate in ices of interstellar medium

    International Nuclear Information System (INIS)

    Iglesias-Groth, S.; Angelini, G.; Cataldo, F.

    2013-01-01

    The γ radiolysis of fullerene C 60 dispersed in H 2 O, H 2 O/NH 3 , H 2 O/methanol and H 2 O/NH 3 /methanol was studied at 250 and 500 kGy. It was found that C 60 originally insoluble in the above mentioned hosting matrix became soluble as a consequence of multiple hydroxylation and oxidation reaction produced by the free radicals generated by the radiolysis of the hosting matrix. The changes undergone by C 60 were studied by infrared spectroscopy (FT-IR) and by electronic absorption spectroscopy. The astrochemical consequences of the present study are that C 60 ejected in the interstellar medium for instance from protoplanetary and planetary nebulae can condense together with water and other ices in dense molecular clouds. Under the action of high energy radiation C 60 reacts with the free radicals generated from the matrix where it is embedded it is solubilized and consequently its carbon content becomes available for further abiotic processes of synthesis of molecules of astrobiological interest. The behavior of C 60 appears comparable to that of common PAHs which are also hydroxylated and oxidized under similar conditions. (author)

  3. C60 Fullerene Effects on Diphenyl-N-(trichloroacetyl)-amidophosphate Interaction with DNA In Silico and Its Cytotoxic Activity Against Human Leukemic Cell Line In Vitro

    Science.gov (United States)

    Grebinyk, A.; Prylutska, S.; Grynyuk, I.; Kolp, B.; Hurmach, V.; Sliva, T.; Amirkhanov, V.; Trush, V.; Matyshevska, O.; Slobodyanik, M.; Prylutskyy, Yu.; Frohme, M.; Ritter, U.

    2018-03-01

    New representative of carbacylamidophosphates - diphenyl-N-(trichloroacetyl)-amidophosphate (HL), which contains two phenoxy substituents near the phosphoryl group, was synthesized, identified by elemental analysis and IR and NMR spectroscopy, and tested as a cytotoxic agent itself and in combination with C60 fullerene. According to molecular simulation results, C60 fullerene and HL could interact with DNA and form a rigid complex stabilized by stacking interactions of HL phenyl groups with C60 fullerene and DNA G nucleotide, as well as by interactions of HL CCl3 group by ion-π bonds with C60 molecule and by electrostatic bonds with DNA G nucleotide. With the use of MTT test, the cytotoxic activity of HL against human leukemic CCRF-CM cells with IC50 value detected at 10 μM concentration at 72 h of cells treatment was shown. Under combined action of 16 μM C60 fullerene and HL, the value of IC50 was detected at lower 5 μM HL concentration and at earlier 48 h period of incubation, besides the cytotoxic effect of HL was observed at a low 2.5 μM concentration at which HL by itself had no influence on cell viability. Binding of C60 fullerene and HL with minor DNA groove with formation of a stable complex is assumed to be one of the possible reasons of their synergistic inhibition of CCRF-CEM cells proliferation. Application of C60 fullerene in combination with 2.5 μM HL was shown to have no harmful effect on structural stability of blood erythrocytes membrane. Thus, combined action of C60 fullerene and HL in a low concentration potentiated HL cytotoxic effect against human leukemic cells and was not followed by hemolytic effect.

  4. Effect of cuprous halide interlayers on the device performance of ZnPc/C60 organic solar cells

    International Nuclear Information System (INIS)

    Lee, Jinho; Park, Dasom; Heo, Ilsu; Yim, Sanggyu

    2014-01-01

    Highlights: • Effect of CuX interlayers on subsequently deposited films and devices was studied. • CuI is the most effective for the performance of ZnPc/C 60 -based solar cells. • Results were related to the molecular geometry of ZnPc and HOMO level of interlayers. - Abstract: The effect of various cuprous halide (CuX) interlayers introduced between a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) layer and zinc phthalocyanine (ZnPc) layer on the physical properties of the ZnPc thin films and device performances of ZnPc/C 60 -based small-molecule organic solar cells was studied. Strong substrate–molecule interaction between the CuX and ZnPc partly converted surface-perpendicular stacking geometry of ZnPc molecules into surface-parallel one. This flat-lying geometry led to an enhancement in electronic absorption and charge transport within the ZnPc films. As a result, the overall power conversion efficiency of the cell with CuI interlayer increased by ∼37%. In the case of the cells with CuBr and CuCl interlayer, however, the enhancement in device performances was limited because of the reduced conversion of the molecular geometry and increased energy barrier for hole extraction due to the low highest occupied molecular orbital level of the interlayer

  5. The performance of selected semi-empirical and DFT methods in studying C60 fullerene derivatives

    Science.gov (United States)

    Sikorska, Celina; Puzyn, Tomasz

    2015-11-01

    The capability of reproducing the open circuit voltages (V oc) of 15 representative C60 fullerene derivatives was tested using the selected quantum mechanical methods (B3LYP, PM6, and PM7) together with the two one-electron basis sets. Certain theoretical treatments (e.g. PM6) were found to be satisfactory for preliminary estimates of the open circuit voltages (V oc), whereas the use of the B3LYP/6-31G(d) approach has been proven to assure highly accurate results. We also examined the structural similarity of 19 fullerene derivatives by employing principle component analysis (PCA). In order to express the structural features of the studied compounds we used molecular descriptors calculated with semi-empirical (PM6 and PM7) and density functional (B3LYP/6-31G(d)) methods separately. In performing PCA, we noticed that semi-empirical methods (i.e. PM6 and PM7) seem satisfactory for molecules, in which one can distinguish the aromatic and the aliphatic parts in the cyclopropane ring of PCBM (phenyl-C61-buteric acid methyl ester) and they significantly overestimate the energy of the highest occupied molecular orbital (E HOMO). The use of the B3LYP functional, however, is recommended for studying methanofullerenes, which closely resemble the structure of PCBM, and for their modifications.

  6. The performance of selected semi-empirical and DFT methods in studying C60 fullerene derivatives

    International Nuclear Information System (INIS)

    Sikorska, Celina; Puzyn, Tomasz

    2015-01-01

    The capability of reproducing the open circuit voltages (V oc ) of 15 representative C 60 fullerene derivatives was tested using the selected quantum mechanical methods (B3LYP, PM6, and PM7) together with the two one-electron basis sets. Certain theoretical treatments (e.g. PM6) were found to be satisfactory for preliminary estimates of the open circuit voltages (V oc ), whereas the use of the B3LYP/6-31G(d) approach has been proven to assure highly accurate results. We also examined the structural similarity of 19 fullerene derivatives by employing principle component analysis (PCA). In order to express the structural features of the studied compounds we used molecular descriptors calculated with semi-empirical (PM6 and PM7) and density functional (B3LYP/6-31G(d)) methods separately. In performing PCA, we noticed that semi-empirical methods (i.e. PM6 and PM7) seem satisfactory for molecules, in which one can distinguish the aromatic and the aliphatic parts in the cyclopropane ring of PCBM (phenyl-C 61 -buteric acid methyl ester) and they significantly overestimate the energy of the highest occupied molecular orbital (E HOMO ). The use of the B3LYP functional, however, is recommended for studying methanofullerenes, which closely resemble the structure of PCBM, and for their modifications. (paper)

  7. Rb-intercalated C60 compounds studied by Inverse Photoemission Spectroscopy

    International Nuclear Information System (INIS)

    Finazzi, M.; Brambilla, A; Biagioni, P.; Cattoni, A.; Duo, L.; Ciccacci, F.; Braicovich, L.; Giovanelli, L.; Goldoni, A.

    2004-01-01

    Full text: Since the discovery of superconductivity in alkali-doped solid C 60 , the electronic structure of the host material (C 60 ) and the doped compounds (A x C 60 , where A is an alkali metal), has been the subject of a considerable amount of work, both theoretical and experimental. The spectroscopic investigations of the alkali-doped C 60 compounds has been mainly focussed on the valence states, while much less information is available on the unoccupied states. In particular, inverse photoemission data on the complete set of stable Rb x C 60 compounds was, so far, still missing. We have performed Inverse Photoemission (IPE) spectroscopy on Rb x C 60 compounds (x = 1, 3, 4, 6). IPE spectra were obtained using a band-pass photon detector (hv = 9.4 eV, FWHM = 0.7 eV) and scanning the kinetic energy of the electrons impinging on the sample. Rb was evaporated on C 60 films (thickness = 6-12 atomic layers) grown in situ on a Cu(100) substrate. The temperature of the substrate was kept equal to T = 100 deg C, which is lower than the C 60 sublimation temperature. The amount of Rb was checked by measuring the intensity of the C1s and Rb3d photoemission lines. After the required amount of Rb had been deposited, the samples were annealed to distillate the desired stable phase

  8. Chemical grafting of Co9S8 onto C60 for hydrogen spillover and storage.

    Science.gov (United States)

    Han, Lu; Qin, Wei; Zhou, Jia; Jian, Jiahuang; Lu, Songtao; Wu, Xiaohong; Fan, Guohua; Gao, Peng; Liu, Boyu

    2017-04-20

    Metal modified C 60 is considered to be a potential hydrogen storage medium due to its high theoretical capacity. Research interest is growing in various hybrid inorganic compounds-C 60 . While the design and synthesis of a novel hybrid inorganic compound-C 60 is difficult to attain, it has been theorized that the atomic hydrogen could transfer from the inorganic compound to the adjacent C 60 surfaces via spillover and surface diffusion. Here, as a proof of concept experiment, we graft Co 9 S 8 onto C 60 via a facile high energy ball milling process. The Raman, XPS, XRD, TEM, HTEM and EELS measurements have been conducted to evaluate the composition and structure of the pizza-like hybrid material. In addition, the electrochemical measurements and calculated results demonstrate that the chemical "bridges" (C-S bonds) between these two materials enhance the binding strength and, hence, facilitate the hydriding reaction of C 60 during the hydrogen storage process. As a result, an increased hydrogen storage capacity of 4.03 wt% is achieved, along with a favorable cycling stability of ∼80% after 50 cycles. Excluding the direct hydrogen storage contribution from Co 9 S 8 in the hybrid paper, the hydrogen storage ability of C 60 was enhanced by 5.9× through the hydriding reaction caused by the Co 9 S 8 modifier. Based on these experimental measurements and theoretical calculations, the unique chemical structure reported here could potentially inspire other C 60 -based advanced hybrids.

  9. Processing of C60 thin films by Matrix-Assisted Pulsed Laser Evaporation (MAPLE)

    DEFF Research Database (Denmark)

    Canulescu, Stela; Schou, Jørgen; Fæster, Søren

    2011-01-01

    Thin films of fullerenes (C60) were deposited onto silicon using matrix-assisted pulsed laser evaporation (MAPLE). The deposition was carried out from a frozen homogeneous dilute solution of C60 in anisole (0.67 wt%), and over a broad range of laser fluences, from 0.15 J/cm2 up to 3.9 J/cm2. MAPLE...

  10. Mono- and bis(pyrrolo)tetrathiafulvalene derivatives tethered to C60

    DEFF Research Database (Denmark)

    Vico Solano, Marta; Della Pia, Eduardo Antonio; Jevric, Martyn

    2014-01-01

    -functionalized MPTTF/BPTTF derivatives, two different tailor-made amino acids, and C-60. Electronic communication between the MPTTF/BPTTF units and the C-60 moieties was studied by a variety of techniques including cyclic voltammetry and absorption spectroscopy. These solution-based studies indicated no observable...

  11. Contributions of different degrees of freedom to thermal transport in the C60 molecular crystal

    Science.gov (United States)

    Kumar, Sushant; Shao, Cheng; Lu, Simon; McGaughey, Alan J. H.

    2018-03-01

    Three models of the C60 molecular crystal are studied using molecular dynamics simulations to resolve the roles played by intermolecular and intramolecular degrees of freedom (DOF) in its structural, mechanical, and thermal properties at temperatures between 35 and 400 K. In the full DOF model, all DOF are active. In the rigid body model, the intramolecular DOF are frozen, such that only center of mass (COM) translations and molecular rotations/librations are active. In the point mass model, the molecule is replaced by a point mass, such that only COM translations are active. The zero-pressure lattice constants and bulk moduli predicted from the three models fall within ranges of 0.15 and 20%. The thermal conductivity of the point mass model is the largest across the temperature range, showing a crystal-like temperature dependence (i.e., it decreases with increasing temperature) due to the presence of phonon modes associated with the COM translations. The rigid body model thermal conductivity is the smallest and follows two distinct regimes. It is crystal-like at low temperatures and becomes temperature invariant at high temperatures. The latter is typical of the behavior of an amorphous material. By calculating the rotational diffusion coefficient, the transition between the two regimes is found to occur at the temperature where the molecules begin to rotate freely. Above this temperature, phonons related to COM translations are scattered by the rotational DOF. The full DOF model thermal conductivity is larger than that of the rigid body model, indicating that intramolecular DOF contribute to thermal transport.

  12. A density functional theory investigation on amantadine drug interaction with pristine and B, Al, Si, Ga, Ge doped C60 fullerenes

    Science.gov (United States)

    Parlak, Cemal; Alver, Özgür

    2017-06-01

    Amantadine is a well-known drug for its treatment effect on Parkinson's disease and influenza infection or hepatitis. Heteroatom doped fullerenes have been extensively examined for their possible usage in sensor technology and medical applications as drug delivery vehicles. In this research, pristine and B, Al, Si, Ga, Ge doped C60 fullerenes and their interaction with amantadine drug molecule were investigated based on the density functional theory calculations. Findings suggest that doped C60 fullerenes might be used to detect the presence of amantadine and they might be used as drug delivery vehicles because of their moderately high adsorption energies with amantadine.

  13. Synthesis and enhanced neuroprotective activity of C60-based ebselen derivatives

    International Nuclear Information System (INIS)

    Liu, X.-F.; Guan, W.-C.; Ke, W.-S.

    2007-01-01

    A C 60 -based ebselen derivative 4 was synthesized through the cycloaddition of C 60 with the azide (3) containing the ebselen component. It was obtained in a four-step synthesis starting from 2-(chloroseleno)benzoyl chloride and 2-(2-aminoethoxy)ethanol in 53% yield (based on consumed C 60 ). Its structure was characterized by 1 H NMR, 13 C NMR, IR, UV, and FAB-MS. To verify that the C 60 -based ebselen derivative 4 had enhanced antioxidative and neuroprotective activity, the C 60 derivative 5 and the ebselen derivative 6 were selected to treat cortical neuronal cells using the same procedures as with the C 60 -based ebselen derivative 4. The cellular viability of different derivative treatment groups was estimated by LDH leakage assay and MTT assay. At the same final concentration (30 μmol/L), the results showed that the antioxidative and protective potencies of the C 60 -based ebselen derivative 4 (MTT (OD) 0.340 ± 0.035, LDH release (UL -1 ) 4.80 ± 0.16) against H 2 O 2 -mediated neuronal injury have an advantage over those of C 60 derivative 5 (MTT (OD) 0.297 ± 0.036, LDH release (UL -1 ) 5.37 ± 0.31) and ebselen derivative 6 (MTT (OD) 0.267 ± 0.027, LDH release (UL -1 ) 5.85 ± 0.26). Correspondingly, the GPX activity of 4 (1.62 U/μmol) was higher than that of 5 (0.77 U/μmol) and 6 (1.24 U/μmol). These findings demonstrate that the incorporation of two components with similar biological activity (C 60 component and ebselen component) may be a desirable way of obtaining a new and more biologically effective C 60 -based compound. (author)

  14. Origin of the Surface-Induced First Hyperpolarizability in the C60/SiO2 System: SCC-DFTB Insight.

    Science.gov (United States)

    Nénon, Sébastien; Champagne, Benoît

    2014-01-02

    Using the self-consistent charge density functional tight binding (SCC-DFTB) method, C60 molecules physisorbed on an α-quartz slab are shown to display a first hyperpolarizability, whereas, owing to their symmetry, both the α-quartz slab and C60 molecule have no first hyperpolarizabilities. A larger first hyperpolarizability is achieved when the lowest-lying (five- or six-membered) ring is situated in between two hydroxyl rows, rather than on top, because this situation favors orbital overlaps and charge transfer. Further analysis has demonstrated that (i) the first hyperpolarizability originates from the MO overlap and field-induced charge transfers from the neighboring substrate/adsorbate moieties but not to geometric relaxation of the C60 molecules at the interface and that (ii) larger first hyperpolarizabilities are associated with low surface coverage and with small distances between C60 and the surface. This contribution is a clear illustration of the emergence of second-order nonlinear optical responses (first hyperpolarizability) as a result of breaking the centrosymmetry.

  15. Volume properties and refraction of aqueous solutions of bisadducts of light fullerene C60 and essential amino acids lysine, threonine, and oxyproline (C60(C6H13N2O2)2, C60(C4H8NO3)2, and C60(C5H9NO2)2) at 25°C

    Science.gov (United States)

    Semenov, K. N.; Ivanova, N. M.; Charykov, N. A.; Keskinov, V. A.; Kalacheva, S. S.; Duryagina, N. N.; Garamova, P. V.; Kulenova, N. A.; Nabieva, A.

    2017-02-01

    Concentration dependences of the density of aqueous solutions of bisadducts of light fullerene C60 and essential amino acids are studied by pycnometry. Concentration dependences of the average molar volumes and partial volumes of components (H2O and corresponding bisadducts) are calculated for C60(C6H13N2O2)2-H2O, C60(C4H8NO3)2-H2O, and C60(C5H9NO2)2-H2O binary systems at 25°C. Concentration dependences of the indices of refraction of C60(C6H13N2O2)2-H2O, C60(C4H8NO3)2-H2O, and C60(C5H9NO2)2-H2O binary systems are determined at 25°C. The concentration dependences of specific refraction and molar refraction of bisadducts and aqueous solutions of them are calculated.

  16. Toxic effect of C60 fullerene-doxorubicin complex towards tumor and normal cells in vitro

    Directory of Open Access Journals (Sweden)

    Prylutska S. V.

    2014-09-01

    Full Text Available Creation of new nanostructures possessing high antitumor activity is an important problem of modern biotechnology. Aim. To evaluate cytotoxicity of created complex of pristine C60 fullerene with the anthracycline antibiotic doxorubicin (Dox, as well as of free C60 fullerene and Dox, towards different cell types – tumor, normal immunocompetent and hepatocytes. Methods. Measurement of size distribution for particles in C60 + Dox mixture was performed by a dynamic light scattering (DLS technique. Toxic effect of C60 + Dox complex in vitro towards tumor and normal cells was studied using the MTT assay. Results. DLS experiment demonstrated that the main fraction of the particles in C60 + Dox mixture had a diameter in the range of about 132 nm. The toxic effect of C60 + Dox complex towards normal (lymphocytes, macrophages, hepatocytes and tumor (Ehrlich ascites carcinoma, leukemia L1210, Lewis lung carcinoma cells was decreased by ~10–16 % and ~7–9 %, accordingly, compared with the same effect of free Dox. Conclusions. The created C60 + Dox composite may be considered as a new pharmacological agent that kills effectively tumor cells in vitro and simultaneously prevents a toxic effect of the free form of Dox on normal cells.

  17. Towards room-temperature superconductivity in low-dimensional C60 nanoarrays: An ab initio study

    Science.gov (United States)

    Erbahar, Dogan; Liu, Dan; Berber, Savas; Tománek, David

    2018-04-01

    We propose to raise the critical temperature Tc for superconductivity in doped C60 molecular crystals by increasing the electronic density of states at the Fermi level N (EF) and thus the electron-phonon coupling constant in low-dimensional C60 nanoarrays. We consider both electron and hole dopings and present numerical results for N (EF) , which increases with the decreasing bandwidth of the partly filled hu- and t1 u-derived frontier bands with the decreasing coordination number of C60. Whereas a significant increase in N (EF) occurs in two-dimensional (2D) arrays of doped C60 intercalated in-between graphene layers, we propose that the highest-Tc values approaching room temperature may occur in bundles of nanotubes filled by one-dimensional (1D) arrays of externally doped C60 or La @C60 or in diluted three-dimensional (3D) crystals where quasi-1D arrangements of C60 form percolation paths.

  18. C(60 fullerene prevents genotoxic effects of doxorubicin in human lymphocytes in vitro

    Directory of Open Access Journals (Sweden)

    K. S. Afanasieva

    2015-02-01

    Full Text Available The self-ordering of C60 fullerene, doxorubicin and their mixture precipitated from aqueous solutions was investigated using atomic-force microscopy. The results suggest the complexation between the two compounds. The genotoxicity of doxorubicin in complex with C60 fullerene (С60+Dox was evaluated in vitro with comet assay using human lymphocytes. The obtained results show that the C60 fullerene prevents the toxic effect of Dox in normal cells and, thus, С60+Dox complex might be proposed for biomedical application.

  19. C 60 as a chemical Faraday cage for three ferromagnetic Fe atoms

    Science.gov (United States)

    Gao, Guohua; Kang, Hong Seok

    2008-09-01

    Based on calculations using density functional theory, we show that C 60 can act as a chemical Faraday cage in which a highly magnetic metal cluster with a high chemical reactivity can be encapsulated. As an example, we find that C 60 can encapsulate a Fe 3 cluster, while it is much less likely to encapsulate a Fe 2 cluster. Spin multiplicity (=9) of the Fe 3@C 60 is very high, being comparable to that (=11) of a free Fe 3 cluster. Geometrically, the triangular plane of the cluster is perpendicular to a S6 axis of the fullerene.

  20. Exciton-dissociation and charge-recombination processes in pentacene/C60 solar cells: theoretical insight into the impact of interface geometry.

    Science.gov (United States)

    Yi, Yuanping; Coropceanu, Veaceslav; Brédas, Jean-Luc

    2009-11-04

    The exciton-dissociation and charge-recombination processes in organic solar cells based on pentacene/C(60) heterojunctions are investigated by means of quantum-mechanical calculations. The electronic couplings and the rates of exciton dissociation and charge recombination have been evaluated for several geometrical configurations of the pentacene/C(60) complex, which are relevant to bilayer and bulk heterojunctions. The results suggest that, irrespective of the actual pentacene-fullerene orientation, both pentacene-based and C(60)-based excitons are able to dissociate efficiently. Also, in the case of parallel configurations of the molecules at the pentacene/C(60) interface, the decay of the lowest charge-transfer state to the ground state is calculated to be very fast; as a result, it can compete with the dissociation process into mobile charge carriers. Since parallel configurations are expected to be found more frequently in bulk heterojunctions than in bilayer heterojunctions, the performance of pentacene/C(60) bulk-heterojunction solar cells is likely to be more affected by charge recombination than that of bilayer devices.

  1. Exciton-Dissociation and Charge-Recombination Processes in Pentacene/C 60 Solar Cells: Theoretical Insight into the Impact of Interface Geometry

    KAUST Repository

    Yi, Yuanping

    2009-11-04

    The exciton-dissociation and charge-recombination processes in organic solar cells based on pentacene/C60 heterojunctions are investigated by means of quantum-mechanical calculations. The electronic couplings and the rates of exciton dissociation and charge recombination have been evaluated for several geometrical configurations of the pentacene/C60 complex, which are relevant to bilayer and bulk heterojunctions. The results suggest that, irrespective of the actual pentacene-fullerene orientation, both pentacene-based and C60-based excitons are able to dissociate efficiently. Also, in the case of parallel configurations of the molecules at the pentacene/C60 interface, the decay of the lowest charge-transfer state to the ground state is calculated to be very fast; as a result, it can compete with the dissociation process into mobile charge carriers. Since parallel configurations are expected to be found more frequently in bulk heterojunctions than in bilayer heterojunctions, the performance of pentacene/C60 bulk-heterojunction solar cells is likely to be more affected by charge recombination than that of bilayer devices. © 2009 American Chemical Society.

  2. Structure and properties of poly(methyl methacrylate) (PMMA)-fullerene (C60) nanocomposites

    Science.gov (United States)

    Kropka, Jamie; Green, Peter

    2006-03-01

    We examined the rheological and dynamical mechanical (DMA) properties of PMMA-C60 nanocomposite materials with relatively low concentrations of C60, 0.1-5wt%. Decreases of the glass transition temperature (Tg), ˜7 ^oC, were observed in samples with 0.5 and 1 wt% C60. The decreases in Tg are connected to decreases of the longest relaxation time measured for the system. The plateau modulus of the composites was enhanced relative to the homopolymer but did not increase monotonically with C60 concentration. The relative changes of the relaxation time, the plateau modulus and Tg cannot be explained by the Doi-Edwards model and appear to be connected to the distribution of the nanoparticles, as determined by electron microscopy.

  3. Attosecond time delay in the valence photoionization of C240 versus C60

    International Nuclear Information System (INIS)

    Shi, Kele; Magrakvelidze, Maia; Anstine, Dylan; Chakraborty, Himadri; Madjet, Mohamed

    2015-01-01

    We investigate effects of electron correlations on the attosecond time delay of the photoionization from HOMO and HOMO-1 electrons in C 240 . A comparison with earlier C 60 results assesses the molecular size effect. (paper)

  4. Infrared transmission study of lanthanide fullerides SmxC60 prepared by metal vapor synthesis

    International Nuclear Information System (INIS)

    Zhao, W.; Simmons, W.B. Jr.; Sweany, R.L.

    1997-01-01

    Lanthanide fulleride Sm x C 60 films were prepared by metal vapor synthesis and the valence state of the C 60 cage in the films was investigated by infrared transmission spectroscopy. Three films with different doping contents of Sm showed red-shift frequencies of F 1u (4) at 1347, 1362 and 1392 (1411) cm -1 , respectively, indicating that the major phase with corresponding valence state n∼-5, -3 and -1 might exist in the films. The other major additional feature of activated pentagonal pinch mode A g (2) was observed at 1445 or 1448 cm -1 in the films, which suggested that the Sm atoms might bond to the five-membered ring of the C 60 cage and ferrocene-like Sm x C 60 complexes might be formed. (orig.)

  5. Synchrotron radiation photoemission spectrum study on K3C60 film

    Institute of Scientific and Technical Information of China (English)

    李宏年; 徐亚伯; 鲍世宁; 李海洋; 何丕模; 钱海杰; 刘风琴; 奎热西·易卜拉欣

    2000-01-01

    K3C60 single crystal film was prepared on the cleaved (111) surface of C60 single crystal. Synchrotron radiation angle-resolved photoemission spectra were measured at normal emission with sample temperature at - 150K. Up to four subpeaks of LUMO-derived band were observed. These sub-peaks exhibit distinct energy dispersions which resemble in general the theoretical ones calculated for K3C60 at low temperature with the so-called one-dimensional disordered structure. But there is large deviation of experimental sub-band intervals from the theoretical values. This result is meaningful for the studies of the physical properties of alkali-doped C60 solids, e.g. the mechanism for superconductivity.

  6. Density Functional Theory Study of the Interaction of Hydrogen with Li6C60.

    Science.gov (United States)

    Wang, Qian; Jena, Puru

    2012-05-03

    Hydrogen storage properties of Li-coated C60 fullerene have been studied using density functional theory within the local density as well as generalized gradient approximation. Hydrogen atoms are found to bind to Li6C60 in two distinct forms, with the first set attaching to C atoms, not linked to Li, in atomic form. Once all such C atoms are saturated with hydrogen, the second set of hydrogen atoms bind quasi-molecularly to the Li atoms, five of which remain in the exohedral and the sixth in the endohedral position. The corresponding hydrogen gravimetric density in Li6C60H40 is 5 wt %. Desorption of hydrogen takes place in succession, the ones bound quasi-molecularly desorbing at a temperature lower than the ones bound atomically. The results are compared with the recent experiment on hydrogen adsorption in Li6C60.

  7. Enhanced room-temperature spin Seebeck effect in a YIG/C60/Pt layered heterostructure

    Science.gov (United States)

    Das, R.; Kalappattil, V.; Geng, R.; Luong, H.; Pham, M.; Nguyen, T.; Liu, Tao; Wu, Mingzhong; Phan, M. H.; Srikanth, H.

    2018-05-01

    We report on large enhancement of the longitudinal spin Seebeck effect (LSSE) in the Y3Fe5O12 (YIG)/Pt system at room temperature due to the addition of a thin layer of organic semiconductor (C60) in between the YIG and the Pt. LSSE measurements show that the LSSE voltage increases significantly, from the initial value of 150 nV for the YIG/Pt structure to 240 nV for the YIG/C60(5nm)/Pt structure. Radio-frequency transverse susceptibility experiments reveal a significant decrease in the surface perpendicular magnetic anisotropy (PMA) of the YIG film when C60 is deposited on it. These results suggest that the LSSE enhancement may be attributed to increased spin mixing conductance, the decreased PMA, and the large spin diffusion length of C60.

  8. Excess electron is trapped in a large single molecular cage C60F60.

    Science.gov (United States)

    Wang, Yin-Feng; Li, Zhi-Ru; Wu, Di; Sun, Chia-Chung; Gu, Feng-Long

    2010-01-15

    A new kind of solvated electron systems, sphere-shaped e(-)@C60F60 (I(h)) and capsule-shaped e(-)@C60F60 (D6h), in contrast to the endohedral complex M@C60, is represented at the B3LYP/6-31G(d) + dBF (diffusive basis functions) density functional theory. It is proven, by examining the singly occupied molecular orbital (SOMO) and the spin density map of e(-)@C60F60, that the excess electron is indeed encapsulated inside the C60F60 cage. The shape of the electron cloud in SOMO matches with the shape of C60F60 cage. These cage-like single molecular solvated electrons have considerably large vertical electron detachment energies VDE of 4.95 (I(h)) and 4.67 eV (D6h) at B3LYP/6-31+G(3df) + dBF level compared to the VDE of 3.2 eV for an electron in bulk water (Coe et al., Int Rev Phys Chem 2001, 20, 33) and that of 3.66 eV for e(-)@C20F20 (Irikura, J Phys Chem A 2008, 112, 983), which shows their higher stability. The VDE of the sphere-shaped e(-)@C60F60 (I(h)) is greater than that of the capsule-shaped e(-)@C60F60 (D6h), indicating that the excess electron prefers to reside in the cage with the higher symmetry to form the more stable solvated electron. It is also noticed that the cage size [7.994 (I(h)), 5.714 and 9.978 A (D6h) in diameter] is much larger than that (2.826 A) of (H2O)20- dodecahedral cluster (Khan, Chem Phys Lett 2005, 401, 85). Copyright 2009 Wiley Periodicals, Inc.

  9. The C60(FeCp22-Based Cell Proliferation Accelerator

    Directory of Open Access Journals (Sweden)

    Andrei Soldatov

    2013-01-01

    Full Text Available We studied structural and magnetic proprieties of the fulleride C60(FeCp22. The influence of fulleride particles on the cell proliferative activity was also investigated. We found that the proliferative activity of the RINmF5 cells increases (53% versus control in presence of the C60(FeCp22 nanosized particles. Moreover, it was registered that the cell culture became multilayered and secreted basophile matrix.

  10. Biodistribution and tumor uptake of C60(OH)x in mice

    International Nuclear Information System (INIS)

    Ji Zhiqiang; Sun Hongfang; Wang Haifang; Xie Qunying; Liu Yuangfang; Wang Zheng

    2006-01-01

    Radiolabeling of fullerol, 125 I-C 60 (OH) x , was performed by the traditional chloramine-T method. The C-I covalent bond in I-C 60 (OH) x was characterized by X-ray photoelectron spectroscopy (XPS) that was sufficiently stable for in vivo study. Laser light scattering spectroscopy clearly showed that C 60 (OH) x aggregated to large nanoparticle clumps with a wide range of distribution. The clumps formed were also visualized by transmission electron microscope (TEM). We examined the biodistribution and tumor uptake of C 60 (OH) x in five mouse bearing tumor models, including mouse H22 hepatocarcinoma, human lung giantcellcarcinoma PD, human colon cancer HCT-8, human gastric cancer MGC803, and human OS732 osteosarcoma. The accumulation ratios of 125 I-C 60 (OH) x in mouse H22 hepatocarcinoma to that in normal muscle tissue (T/N) and blood (T/B) at 1, 6, 24 and 72 h, reveal that 125 I-C 60 (OH) x gradually accumulates in H22 tumor, and retains for a quite long period (e.g., T/N 3.41, T/B 3.94 at 24 h). For the other four tumor models, the T/N ratio at 24 h ranges within 1.21-6.26, while the T/B ratio ranges between 1.23 and 4.73. The accumulation of C 60 (OH) x in tumor is mostly due to the enhanced permeability and retention effect (EPR) and the phagocytosis of mononuclear phagocytes. Hence, C 60 (OH) x might serve as a photosensitizer in the photodynamic therapy of some kinds of tumor

  11. Kelvin probe force microscopy studies of the charge effects upon adsorption of carbon nanotubes and C60 fullerenes on hydrogen-terminated diamond

    Science.gov (United States)

    Kölsch, S.; Fritz, F.; Fenner, M. A.; Kurch, S.; Wöhrl, N.; Mayne, A. J.; Dujardin, G.; Meyer, C.

    2018-01-01

    Hydrogen-terminated diamond is known for its unusually high surface conductivity that is ascribed to its negative electron affinity. In the presence of acceptor molecules, electrons are expected to transfer from the surface to the acceptor, resulting in p-type surface conductivity. Here, we present Kelvin probe force microscopy (KPFM) measurements on carbon nanotubes and C60 adsorbed onto a hydrogen-terminated diamond(001) surface. A clear reduction in the Kelvin signal is observed at the position of the carbon nanotubes and C60 molecules as compared with the bare, air-exposed surface. This result can be explained by the high positive electron affinity of carbon nanotubes and C60, resulting in electron transfer from the surface to the adsorbates. When an oxygen-terminated diamond(001) is used instead, no reduction in the Kelvin signal is obtained. While the presence of a charged adsorbate or a difference in work function could induce a change in the KPFM signal, a charge transfer effect of the hydrogen-terminated diamond surface, by the adsorption of the carbon nanotubes and the C60 fullerenes, is consistent with previous theoretical studies.

  12. Detailed low-energy electron diffraction analysis of the (4×4) surface structure of C60 on Cu(111): Seven-atom-vacancy reconstruction

    Science.gov (United States)

    Xu, Geng; Shi, Xing-Qiang; Zhang, R. Q.; Pai, Woei Wu; Jeng, H. T.; Van Hove, M. A.

    2012-08-01

    A detailed and exhaustive structural analysis by low-energy electron diffraction (LEED) is reported for the C60-induced reconstruction of Cu(111), in the system Cu(111) + (4 × 4)-C60. A wide LEED energy range allows enhanced sensitivity to the crucial C60-metal interface that is buried below the 7-Å-thick molecular layer. The analysis clearly favors a seven-Cu-atom vacancy model (with Pendry R-factor Rp = 0.376) over a one-Cu-atom vacancy model (Rp = 0.608) and over nonreconstructed models (Rp = 0.671 for atop site and Rp = 0.536 for hcp site). The seven-Cu-atom vacancy forms a (4 × 4) lattice of bowl-like holes. In each hole, a C60 molecule can nestle by forming strong bonds (shorter than 2.30 Å) between 15 C atoms of the molecule and 12 Cu atoms of the outermost and second Cu layers.

  13. Diffuse versus square-well confining potentials in modelling A-C60 atoms

    International Nuclear Information System (INIS)

    Dolmatov, V K; King, J L; Oglesby, J C

    2012-01-01

    A perceived advantage for the replacement of a discontinuous square-well pseudo-potential, which is often used by various researchers as an approximation to the actual C 60 cage potential in calculations of endohedral atoms A-C 60 , by a more realistic diffuse potential is explored. The photoionization of endohedral H-C 60 and Xe-C 60 is chosen as the case study. The diffuse potential is modelled by a combination of two Woods-Saxon potentials. It is demonstrated that photoionization spectra of A-C 60 atoms are largely insensitive to the degree η of diffuseness of the potential borders, in a reasonably broad range of ηs. These spectra are found to be insensitive to discontinuity of the square-well potential as well. Both potentials result in practically identical calculated spectra. New numerical values for the set of square-well parameters, which lead to a better agreement between experimental and theoretical data for A-C 60 spectra, are recommended for future studies. (paper)

  14. The effect of C60 doping on the electroluminescent performance of organic light-emitting devices

    International Nuclear Information System (INIS)

    Xu Denghui; Deng Zhenbo; Xiao Jing; Guo Dong; Hao Jingang; Zhang Yuanyuan; Gao Yinhao; Liang Chunjun

    2007-01-01

    Organic light-emitting devices (OLEDs) with the PVK hole transport layer were fabricated. The effect of C 60 doping in the hole transport PVK layer on the performance of the devices was investigated by changing the C 60 content from 0 to 3.0 wt%. The OLEDs had a structure of ITO/PEDOT:PSS/PVK:C 60 (0, 0.5, 1.0, 2.0, 3.0 wt%)/AlQ/LiF/Al. The doping led to a higher conductivity in C 60 -doped PVK layer and the hole mobility of PVK was improved from 4.5x10 -7 to 2.6x10 -6 cm 2 /Vs with the doping concentration of C 60 changing from 0 to 3.0 wt%. Moreover, the doping led to a high density of equilibrium charges carriers, which facilitated hole injection and transport. Doping of C 60 in PVK resulted in efficient hole injection and low drive voltage at high luminance

  15. Development and Characterization of Biocompatible Fullerene [C60]/Amphiphilic Block Copolymer Nanocomposite

    Directory of Open Access Journals (Sweden)

    Alok Chaurasia

    2015-01-01

    Full Text Available We report a supramolecular process for the synthesis of well-defined fullerene (C60/polymer colloid nanocomposites in an aqueous solution via complex formation. A biocompatible triblock poly(4-vinylpyridine-b-polyethylene-b-poly(4-vinylpyridine, P4VP8-b-PEO105-b-P4VP8, was synthesized by atom transfer radical polymerization. The block copolymer formed complexes with C60 in toluene and resulted in fullerene assembly in cluster form. Nanocomposite dispersion in an aqueous solution could be obtained using an aged solution of the polymer/C60/toluene solution by a solvent evaporation technique. The UV-Vis and FTIR spectroscopy confirmed the complex formation of fullerene with the polymer which plays a significant role in controlling the PDI and size of polymer/C60 micelles in the toluene solution. The particle size and morphology of P4VP8-b-PEO105-b-P4VP8 and P4VP8-b-PEO105-b-P4VP8/C60 mixture were studied by dynamic light scattering (DLS and transmission electron microscopy (TEM. In a cytotoxicity test, both pure polymer and the resulting polymer/C60 composite in water showed more than 90% cell viability at 1 mg/mL concentration.

  16. Buckminsterfullerene's (C60) octanol-water partition coefficient (Kow) and aqueous solubility.

    Science.gov (United States)

    Jafvert, Chad T; Kulkarni, Pradnya P

    2008-08-15

    To assess the risk and fate of fullerene C60 in the environment, its water solubility and partition coefficients in various systems are useful. In this study, the log Kow of C60 was measured to be 6.67, and the toluene-water partition coefficient was measured at log Ktw = 8.44. From these values and the respective solubilities of C60 in water-saturated octanol and water-saturated toluene, C60's aqueous solubility was calculated at 7.96 ng/L(1.11 x 10(-11) M) for the organic solvent-saturated aqueous phase. Additionally, the solubility of C60 was measured in mixtures of ethanol-water and tetrahydrofuran-water and modeled with Wohl's equation to confirm the accuracy of the calculated solubility value. Results of a generator column experiment strongly support the hypothesis that clusters form at aqueous concentrations below or near this calculated solubility. The Kow value is compared to those of other hydrophobic organic compounds, and bioconcentration factors for C60 were estimated on the basis of Kow.

  17. Transmission properties of C60 ions through micro- and nano-capillaries

    International Nuclear Information System (INIS)

    Tsuchida, Hidetsugu; Majima, Takuya; Tomita, Shigeo; Sasa, Kimikazu; Narumi, Kazumasa; Saitoh, Yuichi; Chiba, Atsuya; Yamada, Keisuke; Hirata, Koichi; Shibata, Hiromi; Itoh, Akio

    2013-01-01

    We apply the capillary beam-focusing method for the C 60 fullerene projectiles in the velocity range between 0.14 and 0.2 a.u. We study the C 60 transmission properties through two different types of capillaries: (1) borosilicate glass microcapillary with an outlet diameter of 5.5 μm, and (2) Al 2 O 3 multi-capillary foil with a pore size of about 70 nm and a high aspect ratio of about 750. We measured the transmitted particle composition by using the electrostatic deflection method combined with the microchannel plate imaging technique. For the experiments with the single microcapillary, the main transmission component is found to be primary C 60 beams that are focused in the area equal to the capillary outlet diameter. Minor components are charge-exchanged C 60 ions and charged or neutral fragments (fullerene-like C 60-2m and small C n particles), and their fractions decrease with decreasing the projectile velocity. It is concluded that the C 60 transmission fraction is considerably high for both types of the capillaries in the present velocity range

  18. Exploration and characterization of new synthesis methods for C60 colloidal suspensions in water

    Science.gov (United States)

    Hilburn, Martha E.

    Buckminsterfullerene, C60, has been used in the production of several commercial products from badminton racquets and lubricants for their mechanical properties to cosmetics and even dietary supplements for their "antioxidant" properties. Multi-ton production of C60 began in 2003 encouraging serious consideration of its fate in the environment in the case of an accidental release or improper disposal. Although C60 is practically insoluble in water, it readily forms stable aqueous colloidal suspensions (termed nC60) through solvent exchange methods or long-term vigorous stirring in water. Two new solvent exchange methods for synthesizing nC60 are presented. These methods combine key advantages of multiple existing synthesis methods including high yield, narrow particle size distribution, short synthesis time, and an absence of solvents such as tetrahydrofuran that have historically caused problems in laboratory synthesized aggregates. The resulting samples are attractive candidates for use in controlled environmental impact, biological, and toxicity studies. An improved method for quantifying residual solvents in nC60 samples utilizing solid phase micro extraction gas chromatography mass spectrometry (SPME-GC-MS) is also discussed.

  19. Electric-dipole-coupled H2O@C60 dimer: Translation-rotation eigenstates from twelve-dimensional quantum calculations.

    Science.gov (United States)

    Felker, Peter M; Bačić, Zlatko

    2017-02-28

    We report on variational solutions to the twelve-dimensional (12D) Schrödinger equation appertaining to the translation-rotation (TR) eigenstates of H 2 O@C 60 dimer, associated with the quantized "rattling" motions of the two encapsulated H 2 O molecules. Both H 2 O and C 60 moieties are treated as rigid and the cage-cage geometry is taken to be fixed. We consider the TR eigenstates of H 2 O@C 60 monomers in the dimer to be coupled by the electric dipole-dipole interaction between water moieties and develop expressions for computing the matrix elements of that interaction in a dimer basis composed of products of monomer 6D TR eigenstates reported by us recently [P. M. Felker and Z. Bačić, J. Chem. Phys. 144, 201101 (2016)]. We use these expressions to compute TR Hamiltonian matrices of H 2 O@C 60 dimer for two values of the water dipole moment and for various dimer geometries. 12D TR eigenstates of the dimer are then obtained by filter diagonalization. The results reveal two classes of eigenstates, distinguished by the leading order (first or second) at which dipole-dipole coupling contributes to them. The two types of eigenstates differ in the general magnitude of their dipole-induced energy shifts and in the dependence of those shifts on the value of the water dipole moment and on the distance between the H 2 O@C 60 monomers. The dimer results are also found to be markedly insensitive to any change in the orientations of the C 60 cages. Finally, the results lend some support for the interpretation that electric dipole-dipole coupling is at least partially responsible for the apparent reduced-symmetry environment experienced by H 2 O in the powder samples of H 2 O@C 60 [K. S. K. Goh et al., Phys. Chem. Chem. Phys. 16, 21330 (2014)], but only if the water dipole is taken to have a magnitude close to that of free water. The methodology developed in the paper is transferable directly to the calculation of TR eigenstates of larger H 2 O@C 60 assemblies, that will

  20. Impacts of fullerene C60 and virgin olive oil on cadmium-induced genotoxicity in rats.

    Science.gov (United States)

    Aly, Fayza M; Kotb, Ahmed M; Haridy, Mohie A M; Hammad, Seddik

    2018-07-15

    Currently, cadmium is considered to be one of the major environmental pollutants. Environmentally, cadmium is released in various forms e.g. oxide, chloride and sulphide. The aim of the present study was to examine the genotoxic impact of fullerene nanoparticles C 60 (C 60 ) and virgin olive oil (VOO) on cadmium chloride (CdCl 2 )-induced genotoxicity in rats. To evaluate these effects on DNA damage and chromosomal frequency, 25 albino rats were randomly assigned to 5 groups (n=5 per group): Group 1 served as a control; Group 2 received a single intraperitoneal dose of CdCl 2 (3.5mg/kg); Group 3 animals were treated with C 60 (4mg/kg, orally) every other day for 20days; Group 4 received a single intraperitoneal dose of CdCl 2 (3.5mg/kg) and an oral dose of C 60 (4mg/kg); and Group 5 received a single intraperitoneal dose of CdCl 2 (3.5mg/kg) and oral doses of VOO every other day for 20 consecutive days. Genotoxic and anti-genotoxic effects of C 60 and VOO were evaluated in the liver, kidney and bone marrow using molecular and cytogenetic assays. As expected, CdCl 2 and C 60 administration was associated with band number alterations in both liver and kidney; however, C 60 pretreatment recovered to approximately basal number. Surprisingly, C 60 and VOO significantly attenuated the genotoxic effects caused by CdCl 2 in livers and kidneys. In bone marrow, in addition to a reduction in the chromosomal number, several chromosomal aberrations were caused by CdCl 2 . These chromosomal alterations were also reversed by C 60 and VOO. In conclusion, molecular and cytogenetic studies showed that C 60 and VOO exhibit anti-genotoxic agents against CdCl 2 -induced genotoxicity in rats. Further studies are needed to investigate the optimal conditions for potential biomedical applications of these anti-genotoxic agents. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. C60-based ebselen derivative: synthesis by bingel cyclopropanation and enhanced antioxidative and neuroprotective activity

    International Nuclear Information System (INIS)

    Xufeng Liu; Wenchao Guan; Wengshan Ke

    2007-01-01

    C 60 -based ebselen derivative 3 was synthesized through Bingel cyclopropanation of C 60 with the ebselen malonate 2. Compound 3 was obtained in 42% yield (based on consumed C 60 ) in a three-step synthesis starting from 2-(chloroseleno)benzoyl chloride and 2-(2aminoethoxy)ethanol. Its structure was confirmed by 1H NMR, 13 C NMR, IR, UV and FAB-MS spectroscopy analyses. In order to verify the enhanced antioxidative and neuroprotective activity of 3, a C 60 derivative (4), an ebselen derivative (2), and their mixture (4 plus 2 in equimolar ratio) were employed to treat cortical neuronal cells, following the same procedure used with 3 and at the same final concentration (30 μmol L -1 ). Cell viabilities of the four treated groups were estimated by LDH (lactic dehydrogenase) leakage and MTT (3-(4, 5-dimethylthiazole-2yl)-2,5-diphenyl-tetrazolium bromide) assays. Results showed that the antioxidative and protective activities of C 60 -based ebselen derivative 3 against H 2 O 2 -mediated neuronal injury (MTT(OD) 0.364 ± 0.028; LDH release (UL -1 ) 4.66 ± 0.28) were significantly higher than those of C 6 )0 derivative 4 (MTT(OD) 0.324 ± 0.025; LDH release (UL -1 ) 5.39 ± 0.17), ebselen derivative 2 (MTT(OD) 0.294 ± 0.021; LDH release (UL -1 ) 5.71 ± 0.27), and the mixture of 4 and 2 (MTT(OD) 0.310 ± 0.018; LDH release (UL -1 ) 5.54 ±0.39). These findings demonstrated that the combination of two molecular units with similar biological activities (C 60 and ebselen) may be a desirable way of obtaining new and more biologically effective C 60 -based compounds. (author)

  2. Theoretical Study of the Charge-Transfer State Separation within Marcus Theory: The C60-Anthracene Case Study.

    Science.gov (United States)

    Volpi, Riccardo; Nassau, Racine; Nørby, Morten Steen; Linares, Mathieu

    2016-09-21

    We study, within Marcus theory, the possibility of the charge-transfer (CT) state splitting at organic interfaces and a subsequent transport of the free charge carriers to the electrodes. As a case study we analyze model anthracene-C60 interfaces. Kinetic Monte Carlo (KMC) simulations on the cold CT state were performed at a range of applied electric fields, and with the fields applied at a range of angles to the interface to simulate the action of the electric field in a bulk heterojunction (BHJ) interface. The results show that the inclusion of polarization in our model increases CT state dissociation and charge collection. The effect of the electric field on CT state splitting and free charge carrier conduction is analyzed in detail with and without polarization. Also, depending on the relative orientation of the anthracene and C60 molecules at the interface, CT state splitting shows different behavior with respect to both applied field strength and applied field angle. The importance of the hot CT in helping the charge carrier dissociation is also analyzed in our scheme.

  3. Orthorhombic fulleride (CH3NH2)K3C60 close to Mott-Hubbard instability: Ab initio study

    Science.gov (United States)

    Potočnik, Anton; Manini, Nicola; Komelj, Matej; Tosatti, Erio; Arčon, Denis

    2012-08-01

    We study the electronic structure and magnetic interactions in methylamine-intercalated orthorhombic alkali-doped fullerene (CH3NH2)K3C60 within the density functional theory. As in the simpler ammonia intercalated compound (NH3)K3C60, the orthorhombic crystal-field anisotropy Δ lifts the t1u triple degeneracy at the Γ point and drives the system deep into the Mott-insulating phase. However, the computed Δ and conduction electron bandwidth W cannot alone account for the abnormally low experimental Néel temperature, TN=11 K, of the methylamine compound, compared to the much higher value TN=40 K of the ammonia one. Significant interactions between CH3NH2 and C603- are responsible for the stabilization of particular fullerene-cage distortions and the ensuing low-spin S=1/2 state. These interactions also seem to affect the magnetic properties, as interfullerene exchange interactions depend on the relative orientation of deformations of neighboring C603- molecules. For the ferro-orientational order of CH3NH2-K+ groups we find an apparent reduced dimensionality in magnetic exchange interactions, which may explain the suppressed Néel temperature. The disorder in exchange interactions caused by orientational disorder of CH3NH2-K+ groups could further contribute to this suppression.

  4. Giant plasmon excitation in single and double ionization of C60 by fast highly charged Si and O ions

    International Nuclear Information System (INIS)

    Kelkar, A H; Kadhane, U; Misra, D; Tribedi, L C

    2007-01-01

    Se have investigated single and double ionization of C 60 molecule in collisions with 2.33 MeV/u Si q+ (q=6-14) and 3.125 MeV/u O q+ (q=5-8) projectiles. The projectile charge state dependence of the single and double ionization yields of C 60 are then compared to those for an ion-atom collision system using Ne gas as a target. A large difference between the gas and the cluster target behaviour was partially explained in terms of a model based on collective excitation namely the giant dipole plasmon resonance (GDPR). The qualitative agreement between the data and GDPR model prediction for single and double ionization signifies the importance of single and double plasmon excitations in the ionization process. A large deviation of the GDPR model for triple and quadruple ionization from the experimental data imply the importance of the other low impact parameter processes such as evaporation, fragmentation and a possible solid-like dynamical screening

  5. First Production of C60 Nanoparticle Plasma Jet for Study of Disruption Mitigation for ITER

    Science.gov (United States)

    Bogatu, I. N.; Thompson, J. R.; Galkin, S. A.; Kim, J. S.; Brockington, S.; Case, A.; Messer, S. J.; Witherspoon, F. D.

    2012-10-01

    Unique fast response and large mass-velocity delivery of nanoparticle plasma jets (NPPJs) provide a novel application for ITER disruption mitigation, runaway electrons diagnostics and deep fueling. NPPJs carry a much larger mass than usual gases. An electromagnetic plasma gun provides a very high injection velocity (many km/s). NPPJ has much higher ram pressure than any standard gas injection method and penetrates the tokamak confining magnetic field. Assimilation is enhanced due to the NP large surface-to-volume ratio. Radially expanding NPPJs help achieving toroidal uniformity of radiation power. FAR-TECH's NPPJ system was successfully tested: a coaxial plasma gun prototype (˜35 cm length, 96 kJ energy) using a solid state TiH2/C60 pulsed power cartridge injector produced a hyper-velocity (>4 km/s), high-density (>10^23 m-3), C60 plasma jet in ˜0.5 ms, with ˜1-2 ms overall response-delivery time. We present the TiH2/C60 cartridge injector output characterization (˜180 mg of sublimated C60 gas) and first production results of a high momentum C60 plasma jet (˜0.6 g.km/s).

  6. Self-Cleaning Photocatalytic Polyurethane Coatings Containing Modified C60 Fullerene Additives

    Directory of Open Access Journals (Sweden)

    Jeffrey G. Lundin

    2014-08-01

    Full Text Available Surfaces are often coated with paint for improved aesthetics and protection; however, additional functionalities that impart continuous self-decontaminating and self-cleaning properties would be extremely advantageous. In this report, photochemical additives based on C60 fullerene were incorporated into polyurethane coatings to investigate their coating compatibility and ability to impart chemical decontaminating capability to the coating surface. C60 exhibits unique photophysical properties, including the capability to generate singlet oxygen upon exposure to visible light; however, C60 fullerene exhibits poor solubility in solvents commonly employed in coating applications. A modified C60 containing a hydrophilic moiety was synthesized to improve polyurethane compatibility and facilitate segregation to the polymer–air interface. Bulk properties of the polyurethane films were analyzed to investigate additive–coating compatibility. Coatings containing photoactive additives were subjected to self-decontamination challenges against representative chemical contaminants and the effects of additive loading concentration, light exposure, and time on chemical decontamination are reported. Covalent attachment of an ethylene glycol tail to C60 improved its solubility and dispersion in a hydrophobic polyurethane matrix. Decomposition products resulting from oxidation were observed in addition to a direct correlation between additive loading concentration and decomposition of surface-residing contaminants. The degradation pathways deduced from contaminant challenge byproduct analyses are detailed.

  7. Detection of fullerenes (C60 and C70) in commercial cosmetics

    International Nuclear Information System (INIS)

    Benn, Troy M.; Westerhoff, Paul; Herckes, Pierre

    2011-01-01

    Detection methods are necessary to quantify fullerenes in commercial applications to provide potential exposure levels for future risk assessments of fullerene technologies. The fullerene concentrations of five cosmetic products were evaluated using liquid chromatography with mass spectrometry to separate and specifically detect C 60 and C 70 from interfering cosmetic substances (e.g., castor oil). A cosmetic formulation was characterized with transmission electron microscopy, which confirmed that polyvinylpyrrolidone encapsulated C 60 . Liquid-liquid extraction of fullerenes from control samples approached 100% while solid-phase and sonication in toluene extractions yielded recoveries of 27-42%. C 60 was detected in four commercial cosmetics ranging from 0.04 to 1.1 μg/g, and C 70 was qualitatively detected in two samples. A single-use quantity of cosmetic (0.5 g) may contain up to 0.6 μg of C 60 , demonstrating a pathway for human exposure. Steady-state modeling of fullerene adsorption to biosolids is used to discuss potential environmental releases from wastewater treatment systems. - Highlights: → Fullerenes were detected in cosmetics up to 1.1 μg/g. → Liquid-liquid extraction efficiently recovers fullerenes in cosmetic matrices. → Solid-phase extraction reduces LC-MS detection interferences for C60. → Cosmetics can increase human and environmental fullerene exposures. - Fullerenes were detected in cosmetics with liquid chromatography-mass spectrometry up to 1.1 μg/g, demonstrating a source for human/environmental exposure.

  8. Depth profiling using C60+ SIMS-Deposition and topography development during bombardment of silicon

    International Nuclear Information System (INIS)

    Gillen, Greg; Batteas, James; Michaels, Chris A.; Chi, Peter; Small, John; Windsor, Eric; Fahey, Albert; Verkouteren, Jennifer; Kim, K.J.

    2006-01-01

    A C 60 + primary ion source has been coupled to an ion microscope secondary ion mass spectrometry (SIMS) instrument to examine sputtering of silicon with an emphasis on possible application of C 60 + depth profiling for high depth resolution SIMS analysis of silicon semiconductor materials. Unexpectedly, C 60 + SIMS depth profiling of silicon was found to be complicated by the deposition of an amorphous carbon layer which buries the silicon substrate. Sputtering of the silicon was observed only at the highest accessible beam energies (14.5 keV impact) or by using oxygen backfilling. C 60 + SIMS depth profiling of As delta-doped test samples at 14.5 keV demonstrated a substantial (factor of 5) degradation in depth resolution compared to Cs + SIMS depth profiling. This degradation is thought to result from the formation of an unusual platelet-like grain structure on the SIMS crater bottoms. Other unusual topographical features were also observed on silicon substrates after high primary ion dose C 60 + bombardment

  9. Effects of carboxylic acids on nC60 aggregate formation

    International Nuclear Information System (INIS)

    Chang Xiaojun; Vikesland, Peter J.

    2009-01-01

    The discovery that negatively charged aggregates of C 60 fullerene (nC 60 ) are stable in water has raised concerns regarding the potential environmental and health effects of these aggregates. In this work, we show that nC 60 aggregates produced by extended mixing in the presence of environmentally relevant carboxylic acids (acetic acid, tartaric acid, citric acid) have surface charge and morphologic properties that differ from those produced by extended mixing in water alone. In general, aggregates formed in the presence of these acids have a more negative surface charge and are more homogeneous than those produced in water alone. Carboxylic acid identity, solution pH, and sodium ion concentration, which are all intricately coupled, play an important role in setting the measured surface charge. Comparisons between particle sizes determined by analysis of TEM images and those obtained by dynamic light scattering (DLS) indicate that DLS results require careful evaluation when used to describe nC 60 aggregates. - The effects of carboxylic acids on the formation of nC 60 aggregates are discussed

  10. The effect of gate voltage on the electrical transport properties in the contacts of C60 to carbon nanotube leads

    Directory of Open Access Journals (Sweden)

    AA Shokri

    2012-06-01

    Full Text Available  In this paper, we examined the effect of gate voltage, bias voltage, contact geometries and the different bond lengths on the electrical transport properties in a nanostructure consisting of C60 molecule attached to two semi-infinite leads made of single wall carbon nanotubes in the coherent regime. Our calculation was based on the Green’s function method within nearest-neighbour tight-binding approximation. After the calculation was of transmission, the electrical current was obtained by the Landauer-Buttiker formula. Next, the effect of the mentioned factors was investigated in the nanostructure. The application of the present results may be useful in designing devices based on molecular electronics in nanoscale.

  11. Graphene oxide-Li(+)@C60 donor-acceptor composites for photoenergy conversion.

    Science.gov (United States)

    Supur, Mustafa; Kawashima, Yuki; Ohkubo, Kei; Sakai, Hayato; Hasobe, Taku; Fukuzumi, Shunichi

    2015-06-28

    An ionic endohedral metallofullerene (Li(+)@C60) with mild hydrophilic nature was combined with graphene oxide (GO) to construct a donor-acceptor composite in neat water. The resulting composite was characterised by UV-Vis and Raman spectroscopy, powder X-ray diffraction, dynamic light scattering measurements and transmission electron microscopy. Theoretical calculations (DFT at the B3LYP/6-31(d) level) were also utilized to gain further insight into the composite formation. As detected by electron paramagnetic resonance spectroscopy, photoexcitation of the GO-Li(+)@C60 composite results in electron transfer from GO to the triplet excited state of Li(+)@C60, leading to photocurrent generation at the OTE/SnO2 electrode.

  12. C60+ - looking for the bucky-ball in interstellar space

    Science.gov (United States)

    Galazutdinov, G. A.; Shimansky, V. V.; Bondar, A.; Valyavin, G.; Krełowski, J.

    2017-03-01

    The laboratory gas-phase spectrum recently published by Campbell et al. has reinvigorated attempts to confirm the presence of the C_{60}^+ cation in the interstellar medium, through an analysis of the spectra of hot, reddened stars. This search is hindered by at least two issues that need to be addressed: (I) the wavelength range of interest is severely polluted by strong water-vapour lines coming from the Earth's atmosphere; (II) one of the major bands attributed to C_{60}^+, at 9633 Å, is blended with the stellar Mg II line, which is susceptible to non-local thermodynamic equilibrium effects in hot stellar atmospheres. Both these issues are carefully considered here for the first time, based on high-resolution and high signal-to-noise ratio echellé spectra for 19 lines of sight. The result is that the presence of C_{60}^+ in interstellar clouds is brought into question.

  13. Passing Current through Touching Molecules

    DEFF Research Database (Denmark)

    Schull, G.; Frederiksen, Thomas; Brandbyge, Mads

    2009-01-01

    The charge flow from a single C-60 molecule to another one has been probed. The conformation and electronic states of both molecules on the contacting electrodes have been characterized using a cryogenic scanning tunneling microscope. While the contact conductance of a single molecule between two...

  14. Water-soluble C60 fullerenes reduce manifestations of acute cholangitis in rats

    Science.gov (United States)

    Kuznietsova, H. M.; Lynchak, O. V.; Dziubenko, N. V.; Osetskyi, V. L.; Ogloblya, O. V.; Prylutskyy, Yu I.; Rybalchenko, V. K.; Ritter, U.; Scharff, P.

    2018-03-01

    Sclerosing cholangitis is the liver disease of uncertain etiology, extremely unfavorable prognosis and lack of effective medication therapy. Therefore, the effect of water-soluble biocompatible C60 fullerenes (C60FAS) on the liver functional state on rat acute-cholangitis model was aimed to be discovered. Acute cholangitis was simulated by single α-naphthyl isothiocyanate (ANIT, 100 mg/kg) per os administration; C60FAS (0.5 mg/kg) was administered either per os or intraperitoneally in 24 and 48 h after ANIT ingestion, and in 72 h the animals were sacrificed. The activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), the total and direct bilirubin, creatinine and urea in the blood serum were determined, and the liver morphological state was assessed. In animals experienced ANIT-induced acute cholangitis, the total and direct bilirubin, creatinine, ALT, AST, ALP and LDH 1.5-4-fold increase were observed, indicating cytolysis of hepatocytes, cholestasis, and renal dysfunction. The features of periductal fibrosis, biliary epithelium atrophy, and portal-portal linking septa formation were detected, confirming the sclerosing cholangitis development. C60FAS promoted to the normalization of direct and total bilirubin levels, the ALT activity and diminution of fibrotic features. In addition, C60FAS intraperitoneal administration also normalized the ALP activity, indicating the attenuation of disease symptoms. However, the AST activity and creatinine level remained unchanged, and the LDH activity even increased, manifesting the partial persistence of cholestasis and renal dysfunction. Thus, the therapeutic application of C60FAS promotes a partial protection of liver against cholangitis.

  15. A theoretical investigation of the N2O + SO2 reaction on surfaces of P-doped C60 nanocage and Si-doped B30N30 nanocage

    Directory of Open Access Journals (Sweden)

    Meysam Najafi

    Full Text Available The mechanism of N2O reduction via SO2 on surfaces of P-doped C60 and Si-doped B30N30 by density functional theory were investigated. The P and Si adsorption energies on surface of C60 and B30N30 were calculated to be −287.5 and −312.1 kcal/mol, respectively. The decomposition of C60-P-N2O and B30N30-Si-N2O and reduction of C60-P-O∗ and B30N30-Si-O∗ by SO2 molecule were investigated. The B30N30-Si-O∗ has lower activation energy and has more negative ΔGad rather than C60-P-O∗ and therefore the process of B30N30-Si-O∗ + SO2 → B30N30-Si + SO3 was spontaneous more than C60-P-O∗ + SO2 → C60-P + SO3 from thermodynamic view point. Results show that activation energies for B30N30-Si-O∗ + N2O → B30N30-Si-O2 + N2 and C60-P-O∗ + N2O → C60-P-O2 + N2 reactions were 33.23 and 35.82 kcal/mol, respectively. The results show that P-doped C60 and Si-doped B30N30 can be observed as a real catalysts for the reduction of N2O. Keywords: Atom doping, Catalyst, Nanocage, Adsorption, N2O reduction

  16. The interaction of C60 on Si(111 7x7 studied by Supersonic Molecular Beams: interplay between precursor kinetic energy and substrate temperature in surface activated processes.

    Directory of Open Access Journals (Sweden)

    Lucrezia eAversa

    2015-06-01

    Full Text Available Buckminsterfullerene (C60 is a molecule fully formed of carbon that can be used, owing to its electronic and mechanical properties, as clean precursor for the growth of carbon-based materials, ranging from -conjugated systems (graphenes to synthesized species, e.g. carbides such as silicon carbide (SiC. To this goal, C60 cage rupture is the main physical process that triggers material growth. Cage breaking can be obtained either thermally by heating up the substrate to high temperatures (630°C, after C60 physisorption, or kinetically by using Supersonic Molecular Beam Epitaxy (SuMBE techniques. In this work, aiming at demonstrating the growth of SiC thin films by C60 supersonic beams, we present the experimental investigation of C60 impacts on Si(111 7x7 kept at 500°C for translational kinetic energies ranging from 18 to 30 eV. The attained kinetically activated synthesis of SiC submonolayer films is probed by in-situ surface electron spectroscopies (XPS and UPS. Furthermore, in these experimental conditions the C60-Si(111 7×7 collision has been studied by computer simulations based on a tight-binding approximation to Density Functional Theory, DFT. Our theoretical and experimental findings point towards a kinetically driven growth of SiC on Si, where C60 precursor kinetic energy plays a crucial role, while temperature is relevant only after cage rupture to enhance Si and carbon reactivity. In particular, we observe a counterintuitive effect in which for low kinetic energy (below 22 eV, C60 bounces back without breaking more effectively at high temperature due to energy transfer from excited phonons. At higher kinetic energy (22 < K < 30 eV, for which cage rupture occurs, temperature enhances reactivity without playing a major role in the cage break. These results are in good agreement with ab-initio molecular dynamics simulations. SuMBE is thus a technique able to drive materials growth at low temperature regime.

  17. Excimer-laser-irradiation-induced effects in C60 films for photovoltaic applications

    International Nuclear Information System (INIS)

    Narayanan, K.L.; Yamaguchi, M.; Azuma, H.

    2002-01-01

    Thin films of fullerene C 60 deposited by the molecular-beam epitaxy method have been subjected to a 248 nm excimer laser for various timings. Reduction in the electrical resistance of the films and the spectral evolution of the D and G bands in the Raman spectra, due to the sharp tendency towards graphitization accompanied by an increasing level of structural disorder, are observed during laser irradiation. Based on the above results, an attempt has been carried out on these irradiated C 60 films to make a device sandwiched with n-type Si, and the photovoltaic parameters are reported as a function of the laser exposure times

  18. Polymerized phase and amorphous diamond synthesized from C60 fullerene by shock compression

    International Nuclear Information System (INIS)

    Niwase, K.; Homae, T.; Nakamura, K.G.; Kondo, K.

    2006-01-01

    C 60 fullerene films were shock compressed to 23 and 52GPa. Both the recovered samples exhibit fracture into platelets and broad photoluminescence, and intensity of these increases with increasing pressure. At 23GPa, a characteristic single broad band appears at 1560-1570cm -1 , which is similar to the one found for three-dimensional (3D) polymerized C 60 fullerene under high-pressure-high-temperature treatment. At 52GPa, on the other hand, the single broad band has disappeared and a diamond peak sometimes appears, depending on platelets

  19. Effect of fullerene C(60 on ATPase activity and superprecipitation of skeletal muscle actomyosin

    Directory of Open Access Journals (Sweden)

    K. S. Andreichenko

    2013-04-01

    Full Text Available Creation of new biocompatible nanomaterials, which can exhibit the specific biological effects, is an important complex problem that requires the use of last accomplishments of biotechnology. The effect of pristine water-soluble fullerene C60 on ATPase activity and superprecipitation reaction of rabbit skeletal muscle natural actomyosin has been revealed, namely an increase of actomyosin superprecipitation and Мg2+, Са2+– and K+-ATPase activity by fullerene was investigated. We conclude that this finding offers a real possibility for the regulation of contraction-relaxation of skeletal muscle with fullerene C60.

  20. Energy-level alignment at interfaces between manganese phthalocyanine and C60

    Directory of Open Access Journals (Sweden)

    Daniel Waas

    2017-04-01

    Full Text Available We have used photoelectron spectroscopy to determine the energy-level alignment at organic heterojunctions made of manganese phthalocyanine (MnPc and the fullerene C60. We show that this energy-level alignment depends upon the preparation sequence, which is explained by different molecular orientations. Moreover, our results demonstrate that MnPc/C60 interfaces are hardly suited for application in organic photovoltaic devices, since the energy difference of the two lowest unoccupied molecular orbitals (LUMOs is rather small.

  1. Theoretical Studies on Electronic States of Rh-C60. Possibility of a Room-temperature Organic Ferromagnet

    Directory of Open Access Journals (Sweden)

    K. Yamaguchi

    2004-08-01

    Full Text Available A possible mechanism for a ferromagnetic interaction in the rhombic (Rh formof C60 (Rh-C60 is suggested on the basis of theoretical studies in relation to cage distortionof the C60 unit in the polymerized 2D-plane. Band structure calculations on Rh-C60 showthat cage distortion leads to competition between diamagnetic and ferromagnetic states,which give rise to the possibility of thermally populating the ferromagnetic state.

  2. Effects of carbon nanomaterials fullerene C60 and fullerol C60(OH)18–22 on gills of fish Cyprinus carpio (Cyprinidae) exposed to ultraviolet radiation

    International Nuclear Information System (INIS)

    Socoowski Britto, Roberta; Longaray Garcia, Márcia; Martins da Rocha, Alessandra; Artigas Flores, Juliana; Pinheiro, Maurício V. Brant; Monserrat, José María; Ribas Ferreira, Josencler L.

    2012-01-01

    In consequence of their growing use and demand, the inevitable environmental presence of nanomaterials (NMs) has raised concerns about their potential deleterious effects to aquatic environments. The carbon NM fullerene (C 60 ), which forms colloidal aggregates in water, and its water-soluble derivative fullerol (C 60 (OH) 18–22 ), which possesses antioxidant properties, are known to be photo-excited by ultraviolet (UV) or visible light. To investigate their potential hazards to aquatic organisms upon exposure to UV sunlight, this study analyzed (a) the in vitro behavior of fullerene and fullerol against peroxyl radicals (ROO·) under UV-A radiation and (b) the effects of these photo-excited NMs on oxidative stress parameters in functional gills extracted from the fish Cyprinus carpio (Cyprinidae). The variables measured were the total antioxidant capacity, lipid peroxidation (TBARS), the activities of the antioxidant enzymes glutathione reductase (GR) and glutamate cysteine ligase (GCL), and the levels of the non-enzymatic antioxidant glutathione (GSH). The obtained results revealed the following: (1) both NMs behaved in vitro as antioxidants against ROO· in the dark and as pro-oxidants in presence of UV-A, the latter effect being reversed by the addition of sodium azide, which is a singlet oxygen ( 1 O 2 ) quencher; (2) fullerene induced toxicity with or without UV-A incidence, with a significant (p 1 O 2 generation; and (3) fullerol also decreased GCL activity and GSH formation (p 1 O 2 formation.

  3. Efficient Energy Sensitization of C 60 and Application to Organic Photovoltaics

    KAUST Repository

    Trinh, Cong

    2013-08-14

    Fullerenes are currently the most popular electron-acceptor material used in organic photovoltaics (OPVs) due to their superior properties, such as good electron conductivity and efficient charge separation at the donor/acceptor interface. However, low absorptivity in the visible spectral region is a significant drawback of fullerenes. In this study, we have designed a zinc chlorodipyrrin derivative (ZCl) that absorbs strongly in the visible region (450-600 nm) with an optical density 7-fold higher than a C60 film. ZCl efficiently transfers absorbed photoenergy to C60 in mixed films. Application of ZCl as an energy sensitizer in OPV devices leads to an increase in the photocurrent from the acceptor layer, without changing the other device characteristics, i.e., open circuit voltage and fill factor. For example, C 60-based OPVs with and without the sensitizer give 4.03 and 3.05 mA/cm2, respectively, while both have VOC = 0.88 V and FF = 0.44. Our ZCl sensitization approach improves the absorbance of the electron-acceptor layer while still utilizing the beneficial characteristics of C60 in OPVs. © 2013 American Chemical Society.

  4. Collisions of Oq+ with neutral C-60 : Charge transfer and fragmentation

    NARCIS (Netherlands)

    Schlatholter, T; Hoekstra, R; Morgenstern, R

    1998-01-01

    Fragmentation of C-60 fullerenes by collisions with multiply charged Oq+ ions (1 less than or equal to q less than or equal to 7) has been studied experimentally for Oq+ collision energies of 1.16 keV amu(-1) For high projectile charges the potential energy of the projectiles is mainly responsible

  5. Removal of aqueous nC60 fullerene from water by low pressure membrane filtration

    NARCIS (Netherlands)

    Floris, R.; Nijmeijer, K.; Cornelissen, E. R.

    2016-01-01

    The potential environmental and health risks of engineered nanoparticles such as buckminsterfullerene C60 in water require their removal during the production of drinking water. We present a study focusing on (i) the removal mechanism and (ii) the elucidation of the role of the membrane pore size

  6. Modified denatured lysozyme effectively solubilizes fullerene c60 nanoparticles in water

    Science.gov (United States)

    Siepi, Marialuisa; Politi, Jane; Dardano, Principia; Amoresano, Angela; De Stefano, Luca; Monti, Daria Maria; Notomista, Eugenio

    2017-08-01

    Fullerenes, allotropic forms of carbon, have very interesting pharmacological effects and engineering applications. However, a very low solubility both in organic solvents and water hinders their use. Fullerene C60, the most studied among fullerenes, can be dissolved in water only in the form of nanoparticles of variable dimensions and limited stability. Here the effect on the production of C60 nanoparticles by a native and denatured hen egg white lysozyme, a highly basic protein, has been systematically studied. In order to obtain a denatured, yet soluble, lysozyme derivative, the four disulfides of the native protein were reduced and exposed cysteines were alkylated by 3-bromopropylamine, thus introducing eight additional positive charges. The C60 solubilizing properties of the modified denatured lysozyme proved to be superior to those of the native protein, allowing the preparation of biocompatible highly homogeneous and stable C60 nanoparticles using lower amounts of protein, as demonstrated by dynamic light scattering, transmission electron microscopy and atomic force microscopy studies. This lysozyme derivative could represent an effective tool for the solubilization of other carbon allotropes.

  7. Improved spectrophotometric analysis of fullerenes C60 and C70 in high-solubility organic solvents.

    Science.gov (United States)

    Törpe, Alexander; Belton, Daniel J

    2015-01-01

    Fullerenes are among a number of recently discovered carbon allotropes that exhibit unique and versatile properties. The analysis of these materials is of great importance and interest. We present previously unreported spectroscopic data for C60 and C70 fullerenes in high-solubility solvents, including error bounds, so as to allow reliable colorimetric analysis of these materials. The Beer-Lambert-Bouguer law is found to be valid at all wavelengths. The measured data were highly reproducible, and yielded high-precision molar absorbance coefficients for C60 and C70 in o-xylene and o-dichlorobenzene, which both exhibit a high solubility for these fullerenes, and offer the prospect of improved extraction efficiency. A photometric method for a C60/C70 mixture analysis was validated with standard mixtures, and subsequently improved for real samples by correcting for light scattering, using a power-law fit. The method was successfully applied to the analysis of C60/C70 mixtures extracted from fullerene soot.

  8. The effects of encapsulating C60 fullerenes on the bending flexibility of carbon nanotubes

    International Nuclear Information System (INIS)

    Zhu, J; Pan, Z Y; Wang, Y X; Zhou, L; Jiang, Q

    2007-01-01

    We investigate the bending flexibility of carbon nanotubes (CNTs) with encapsulated C 60 fullerenes, using molecular dynamics (MD) simulations. Our simulations on the bending of the fully ((C 60 ) 12 -(10,10)) and partially ((C 60 ) 10 -(10,10)) filled peapods show an 18 and 6.3% increase of the flexural rigidity, and a 45 and 11% increase of the buckling strength, respectively, compared to the empty (10, 10) CNT. What is characteristically different for the peapod from the empty CNT is the presence of a transitional region in the loading process that proceeds to the onset of buckling. Within this transitional region, the interaction between the encapsulated fullerenes and the hosting CNT leads to an unusual configuration of the peapod, in which there are ripples along the inner arc of the bent peapod. The transition region in the partially filled peapod is short compared with the fully filled peapod. This is mainly caused by the axial motion of C 60 fullerenes, especially after the appearance of the small ripple. The rippling configuration has been reported previously in the bending of multi-walled CNTs, where it emerges after the critical bending angle. However, in the present case, the peapod remains perfectly elastic in this transitional region until buckling takes place

  9. Conformational, IR spectroscopic and electronic properties of conium alkaloids and their adducts with C60 fullerene

    Science.gov (United States)

    Zabolotnyi, M. A.; Prylutskyy, Yu I.; Poluyan, N. A.; Evstigneev, M. P.; Dovbeshko, G. I.

    2016-08-01

    Conformational, IR spectroscopic and electronic properties of the components of Conium alkaloids (Conium maculatum) in aqueous environment were determined by model calculations and experiment. With the help of FT-IR spectroscopy the possibility of formation of an adduct between γ-coniceine alkaloid and C60 fullerene was demonstrated, which is important for further application of conium analogues in biomedical purposes.

  10. UV/Vis spectroscopy of C60 embedded in water ice

    DEFF Research Database (Denmark)

    Cuylle, Steven; Linnartz, Harold; Thrower, John

    2012-01-01

    Electronic solid state spectra are recorded for C60 embedded in 40 K water ice using broad band direct absorption spectroscopy, and assigned with reference to existing matrix data. The results are interesting in view of the recent gas phase detection of fullerenes in the interstellar medium...

  11. C59N+ and C69N+: isoelectronic heteroanalogues of C60 and C70

    International Nuclear Information System (INIS)

    Lamparth, I.; Nuber, B.; Schick, G.; Skiebe, A.; Groesser, T.; Hirsch, A.

    1995-01-01

    Fragmentation reactions in the mass spectrometer were used to generate the first characterized nitrogen heterofullerene ions C 59 N + and C 69 N + from regioselectively synthesized oligoiminofullerenes. During this process one carbon atom in the fullerene core is removed and replaced with a nitrogen atom. C 59 N + has almost the same structure as the isoelectronic C 60 . (orig.)

  12. Preparative-scale separation of C60 and C70 on polystyrene gel

    International Nuclear Information System (INIS)

    Guegel, A.; Becker, M.; Hammel, D.; Mindach, L.; Raeder, J.; Simon, T.; Wagner, M.; Muellen, K.

    1992-01-01

    Five grams of a mixture of C 60 /C 70 can be separated in 24 hours by gel permeation chromatography on polystyrene gel. The mobile phase can be completely recovered, and the method can be scaled up by a simple increase in the inner diameter of the column. (orig.) [de

  13. C60 exposure induced tissue damage and gene expression alterations in the earthworm Lumbricus rubellus

    NARCIS (Netherlands)

    Ploeg, van der M.J.C.; Handy, R.D.; Heckmann, L.H.; Hout, van der A.; Brink, van den N.W.

    2013-01-01

    Effects of C60 exposure (0, 15 or 154 mg/kg soil) on the earthworm Lumbricus rubellus were assessed at the tissue and molecular level, in two experiments. In the first experiment, earthworms were exposed for four weeks, and in the second lifelong. In both experiments, gene expression of heat shock

  14. C60 Recognition from Extended Tetrathiafulvalene Bis-acetylide Platinum(II) Complexes.

    Science.gov (United States)

    Bastien, Guillaume; Dron, Paul I; Vincent, Manon; Canevet, David; Allain, Magali; Goeb, Sébastien; Sallé, Marc

    2016-11-18

    The favorable spatial organization imposed by the square planar 4,4'-di(tert-butyl)-2,2'-bipyridine (dbbpy) platinum(II) complex associated with the electronic and shape complementarity of π-extended tetrathiafulvalene derivatives (exTTF) toward fullerenes is usefully exploited to construct molecular tweezers, which display good affinities for C 60 .

  15. A BPTTF-based self-assembled electron-donating triangle capable of C60 binding.

    Science.gov (United States)

    Goeb, Sébastien; Bivaud, Sébastien; Dron, Paul Ionut; Balandier, Jean-Yves; Chas, Marcos; Sallé, Marc

    2012-03-25

    A kinetically stable self-assembled redox-active triangle is isolated. The resulting electron-donating cavity, which incorporates three BPTTF units, exhibits a remarkable binding ability for electron-deficient C(60), supported by a favorable combination of structural and electronic features.

  16. Sodium doping in copper-phthalocyanine/C60 heterojunction for organic photovoltaic applications

    International Nuclear Information System (INIS)

    Chen, Hui-Ju; Wu, Hsuan-Ta; Hung, Kuang-Teng; Fu, Sheng-Wen; Shih, Chuan-Feng

    2013-01-01

    Sodium was incorporating at the copper-phthalocyanine (CuPc)/C 60 interface in CuPc/C 60 -based small-molecular solar cells to enhance their power conversion efficiency. C 60 was deposited on slightly sodium-doped CuPc. Post-annealing improved the cell properties. Post-annealing doubled the conversion efficiency of the least sodium-doped devices (75 °C, 40 min). The electron/hole mobility ratio gradually approached unity as the annealing time increased, indicating that a reduction in the space charge accumulation was the main cause of the increase of the short-circuit current. The mechanism of enhancement of carrier transport by annealing was investigated by making capacitance–voltage measurements and performing corresponding depth-profile analyses. - Highlights: • Incorporate Na at copper-phthalocyanine/C 60 interface • Annealing importantly improved the cell efficiency of Na-doped devices. • Change in the carrier mobility and concentration was investigated

  17. Efficient Energy Sensitization of C 60 and Application to Organic Photovoltaics

    KAUST Repository

    Trinh, Cong; Kirlikovali, Kent O.; Bartynski, Andrew N.; Tassone, Christopher J.; Toney, Michael F.; Burkhard, George F.; McGehee, Michael D.; Djurovich, Peter I.; Thompson, Mark E.

    2013-01-01

    Fullerenes are currently the most popular electron-acceptor material used in organic photovoltaics (OPVs) due to their superior properties, such as good electron conductivity and efficient charge separation at the donor/acceptor interface. However, low absorptivity in the visible spectral region is a significant drawback of fullerenes. In this study, we have designed a zinc chlorodipyrrin derivative (ZCl) that absorbs strongly in the visible region (450-600 nm) with an optical density 7-fold higher than a C60 film. ZCl efficiently transfers absorbed photoenergy to C60 in mixed films. Application of ZCl as an energy sensitizer in OPV devices leads to an increase in the photocurrent from the acceptor layer, without changing the other device characteristics, i.e., open circuit voltage and fill factor. For example, C 60-based OPVs with and without the sensitizer give 4.03 and 3.05 mA/cm2, respectively, while both have VOC = 0.88 V and FF = 0.44. Our ZCl sensitization approach improves the absorbance of the electron-acceptor layer while still utilizing the beneficial characteristics of C60 in OPVs. © 2013 American Chemical Society.

  18. Pressure dependence of the superconducting transition temperature of Rb3C60 up to 20 kbar

    International Nuclear Information System (INIS)

    Bud'ko, S.L.; Meng, R.L.; Chu, C.W.; Hor, P.H.

    1991-01-01

    AC susceptibility measurements of Rb 3 C 60 under hydrostatic pressure up to 20 kbar are reported. The superconducting transition temperature (T c ) decreases linearly under pressure with the pressure derivative dT c /dP = -0.78 K degrees/kbar

  19. Optical conductivity in A3C60 (A=K, Rb)

    NARCIS (Netherlands)

    Brink, J. van den; Gunnarsson, O.; Eyert, V.

    1997-01-01

    Published in: Phys. Rev. B 57 (1998) 2163-2167 Citing articles (CrossRef) citations recorded in [Science Citation Index] Abstract: We study the optical conductivity in A3C60 (A =K, Rb). The effects of the electron-phonon interaction is included to lowest order in the coupling strength lambda. It is

  20. Diels-Alder cyclo-addition as an efficient tool for linking π-donors onto fullerene C60

    International Nuclear Information System (INIS)

    Hudhomme, P.

    2006-01-01

    Diels-Alder reaction of endo-cyclic, acyclic 1,3-dienes or (hetero) o-quinodimethanes with the dienophilic fullerene C 60 is presented as an efficient tool for linking electro-active units giving rise to systems where both the donor and C 60 partners take up well defined volumes and orientations with respect to one another. While porphyrin is the most frequently used electron donor in artificial photosynthetic models, C 60 -based tetrathiafulvalene (TTF) or p-conjugated oligomer adducts remain interesting candidates for the preparation of photovoltaic devices. In this account, we focus on the use of the Diels-Alder cyclo-addition and its use in the synthesis of TTF-C 60 dyads, (TTF) n -C 60 polyads and C 60 -TTF-C 60 dumbbells as part of ongoing research into materials which display efficient photo-induced electron transfer. (author)

  1. Computational study for the circular redox reaction of N2O with CO catalyzed by fullerometallic cations C60Fe+ and C70Fe.

    Science.gov (United States)

    Anafcheh, Maryam; Naderi, Fereshteh; Khodadadi, Zahra; Ektefa, Fatemeh; Ghafouri, Reza; Zahedi, Mansour

    2017-03-01

    We applied density functional calculations to study the circular redox reaction mechanism of N 2 O with CO catalyzed by fullerometallic cations C 60 Fe + and C 70 Fe + . The on-top sites of six-membered rings (η 6 ) of fullerene cages are the most preferred binding sites for Fe + cation, and the hexagon to pentagon migration of Fe + is unlikely under ambient thermodynamic conditions. The initial ion/molecule reaction, N 2 O rearrangement and N 2 abstraction on the considered fullerometallic cations are easier than those on the bare Fe + cation in the gas phase. Generally, our results indicate that fullerometallic ions, C 60 Fe + and C 70 Fe + , are more favorable substrates for redox reaction of N 2 O with CO in comparison to the other previously studied carbon nanostructures such as graphene and nanotubes. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Recent Advances in Electrochemical Biosensors Based on Fullerene-C60 Nano-Structured Platforms.

    Science.gov (United States)

    Pilehvar, Sanaz; De Wael, Karolien

    2015-11-23

    Nanotechnology is becoming increasingly important in the field of (bio)sensors. The performance and sensitivity of biosensors is greatly improved with the integration of nanomaterials into their construction. Since its first discovery, fullerene-C60 has been the object of extensive research. Its unique and favorable characteristics of easy chemical modification, conductivity, and electrochemical properties has led to its tremendous use in (bio)sensor applications. This paper provides a concise review of advances in fullerene-C60 research and its use as a nanomaterial for the development of biosensors. We examine the research work reported in the literature on the synthesis, functionalization, approaches to nanostructuring electrodes with fullerene, and outline some of the exciting applications in the field of (bio)sensing.

  3. Coupled cluster calculations for static and dynamic polarizabilities of C60

    Science.gov (United States)

    Kowalski, Karol; Hammond, Jeff R.; de Jong, Wibe A.; Sadlej, Andrzej J.

    2008-12-01

    New theoretical predictions for the static and frequency dependent polarizabilities of C60 are reported. Using the linear response coupled cluster approach with singles and doubles and a basis set especially designed to treat the molecular properties in external electric field, we obtained 82.20 and 83.62 Å3 for static and dynamic (λ =1064 nm) polarizabilities. These numbers are in a good agreement with experimentally inferred data of 76.5±8 and 79±4 Å3 [R. Antoine et al., J. Chem. Phys.110, 9771 (1999); A. Ballard et al., J. Chem. Phys.113, 5732 (2000)]. The reported results were obtained with the highest wave function-based level of theory ever applied to the C60 system.

  4. Temperature-dependent nucleation and capture-zone scaling of C 60 on silicon oxide

    Science.gov (United States)

    Groce, M. A.; Conrad, B. R.; Cullen, W. G.; Pimpinelli, A.; Williams, E. D.; Einstein, T. L.

    2012-01-01

    Submonolayer films of C 60 have been deposited on ultrathin SiO 2 films for the purpose of characterizing the initial stages of nucleation and growth as a function of temperature. Capture zones extracted from the initial film morphology were analyzed using both the gamma and generalized Wigner distributions. The calculated critical nucleus size i of the C 60 islands was observed to change over the temperature range 298 K to 483 K. All fitted values of i were found to be between 0 and 1, representing stable monomers and stable dimers, respectively. With increasing temperature of film preparation, we observed i first increasing through this range and then decreasing. We discuss possible explanations of this reentrant-like behavior.

  5. Low energy ion implantation and high energy heavy ion irradiation in C60 films

    International Nuclear Information System (INIS)

    Narayanan, K.L.; Yamaguchi, M.; Dharmarasu, N.; Kojima, N.; Kanjilal, D.

    2001-01-01

    C 60 films have been bombarded with low energy boron ions and high energy swift heavy ions (SHI) of silver and oxygen at different doses. Raman scattering and Fourier transform infrared (FTIR) studies were carried out on the virgin and irradiated films and the results are in good agreement with each other. The films subject to low energy boron ion implantation showed destruction of the bukky balls whereas the films subject to high energy ion irradiation did not show appreciable effects on their structure. These results indicate that C 60 films are more prone to defects by elastic collision and subsequent implantation at lower energy. Irradiation at higher energy was less effective in creating appreciable defects through electronic excitation by inelastic collisions at similar energy density

  6. In situ Raman study of C60 polymerization during isothermal pressurizing at 800 K

    International Nuclear Information System (INIS)

    Talyzin, A V; Dubrovinsky, L S

    2004-01-01

    The first in situ Raman study of C 60 isothermal compression at 800 K and up to 32 GPa was performed using rhombohedral and tetragonal phases as starting materials. The rhombohedral phase shows a phase transition to 3D polymer above 10 GPa, similar to that in experiments where isobaric heating was used at pressures of 9-13 GPa. It is shown that the T-P diagram of C 60 polymeric phases (temperature increase followed by pressurizing) is significantly different from the known P-T diagram (pressurizing followed by heating). Tetragonal polymer exhibited significantly stronger stability and can be followed at least up to ∼15 GPa. Heating up to 800 K of tetragonal polymer at pressures of 6-8 GPa confirms that, due to geometrical frustrations, the tetragonal phase remains stable even at pressure and temperature conditions at which rhombohedral polymer is usually formed

  7. Improving efficiency of pentacene/C60 based solar cells with mixed interlayers

    International Nuclear Information System (INIS)

    Hung, Kuang-Teng; Huang, Kuan-Ta; Hsiao, Chu-Yun; Shih, Chuan-Feng

    2011-01-01

    This work presents a modified architecture for conventional pentacene/fullerene (C 60 ) solar cells by inserting alternately deposited C 60 /pentacene interlayers (∼ 1-2 nm per layer). The cell parameters, the incident photon-to-current efficiency spectra and the atomic force microscopy were used to characterize devices that had different numbers of inserting layers. The power conversion efficiency (PCE) increased markedly from 0.77 to 1.60% as the number of the inserted pairs increased from zero to three. The PCE further increased to 1.73% after post-annealing. The interlayers formed an interpenetrating network, enlarging the area over which excitons dissociate. When the number of interlayers and post-annealing conditions were optimized, the resistance and the surface roughness were minimized. When the number of pairs was increased to five, cell performance was degraded. The mechanism by which the properties of the solar cells are related to the inserted layers is presented.

  8. Epitaxial Growth of an Organic p-n Heterojunction: C60 on Single-Crystal Pentacene.

    Science.gov (United States)

    Nakayama, Yasuo; Mizuno, Yuta; Hosokai, Takuya; Koganezawa, Tomoyuki; Tsuruta, Ryohei; Hinderhofer, Alexander; Gerlach, Alexander; Broch, Katharina; Belova, Valentina; Frank, Heiko; Yamamoto, Masayuki; Niederhausen, Jens; Glowatzki, Hendrik; Rabe, Jürgen P; Koch, Norbert; Ishii, Hisao; Schreiber, Frank; Ueno, Nobuo

    2016-06-01

    Designing molecular p-n heterojunction structures, i.e., electron donor-acceptor contacts, is one of the central challenges for further development of organic electronic devices. In the present study, a well-defined p-n heterojunction of two representative molecular semiconductors, pentacene and C60, formed on the single-crystal surface of pentacene is precisely investigated in terms of its growth behavior and crystallographic structure. C60 assembles into a (111)-oriented face-centered-cubic crystal structure with a specific epitaxial orientation on the (001) surface of the pentacene single crystal. The present experimental findings provide molecular scale insights into the formation mechanisms of the organic p-n heterojunction through an accurate structural analysis of the single-crystalline molecular contact.

  9. An Experimental study of Fullerene (C60) Nano-fluids on Pool Boiling Conditions

    International Nuclear Information System (INIS)

    Melani, Ai; Shin, Byoong Su; Chang, Soon Heung

    2009-01-01

    Critical heat flux (CHF) is directly related to the performance of the system since CHF limits the heat transfer of a heat transfer system. Significant enhancement of CHF allows reliable operation of equipment with more margins to operational limit and more economic cost saving. The previous results show that the nano-fluids significantly enhanced pool boiling CHF compared to pure water. It was supposed that CHF enhancement was due to increased thermal conductivity of fluids, change of bubble shape and behavior, and nano-particle coating of the boiling surface. The previous researches also show that mainly the pool boiling experiment was employed metal particles. Fullerene (C 60 ) is a novel carbon allotrope that was first discovered in 1985 by a winner noble 'Sir Harold W.Kroto, Richard E. Smalley and Robert F.Curl Jr'. In this study we report the first CHF experiment in pool boiling conditions using Fullerene (C 60 ) nanofluids

  10. Possible superstructures of metallic ions in nonstoichiometric fullerites Mx C60

    International Nuclear Information System (INIS)

    Loktev, V.M.; Tatarenko, O.M.

    1993-01-01

    The ordered structures of alkali metal M=K,Rb,Cs atoms are considered in the M x C 60 systems for x<6 on the basis of symmetry analysis. Using the static concentration wave approach the x values and the corresponding vectors resulting in periodic structures are determined. The phase diagram that agrees qualitatively with the one observed experimentally is obtained. (author). 17 refs., 10 figs

  11. Product Characterization and Headspace Analysis of Solar Irradiated Aqueous C60 Clusters

    OpenAIRE

    Su, Dan

    2013-01-01

    Buckminsterfullerene (C60) is an important fullerene material that has drawn much attention and is currently being applied in many different fields. It was discovered in 1985. As its production has largely increased to meet these industrial needs, it is obvious that its environmental occurrence, especially in aqueous systems, will occur. To further provide information for environmental toxicity studies and for its risk assessment, this thesis focuses on the photo transformation processes of a...

  12. Reprint of: Negative carbon cluster ion beams: New evidence for the special nature of C60

    Science.gov (United States)

    Liu, Y.; O'brien, S. C.; Zhang, Q.; Heath, J. R.; Tittel, F. K.; Curl, R. F.; Kroto, H. W.; Smalley, R. E.

    2013-12-01

    Cold carbon cluster negative ions are formed by supersonic expansion of a plasma created at the nozzle of a supersonic cluster beam source by an excimer laser pulse. The observed distribution of mass peaks for the Cn- ions for n > 40 demonstrates that the evidence previously given for the special stability of neutral C60 and the existence of spheroidal carbon shells cannot be an artifact of the ionization conditions.

  13. Effect of magnetic fullerene on magnetization reversal created at the Fe/C60 interface.

    Science.gov (United States)

    Mallik, Srijani; Mattauch, Stefan; Dalai, Manas Kumar; Brückel, Thomas; Bedanta, Subhankar

    2018-04-03

    Probing the hybridized magnetic interface between organic semiconductor (OSC) and ferromagnetic (FM) layers has drawn significant attention in recent years because of their potential in spintronic applications. Recent studies demonstrate various aspects of organic spintronics such as magnetoresistance, induced interface moment etc. However, not much work has been performed to investigate the implications of such OSC/FM interfaces on the magnetization reversal and domain structure which are the utmost requirements for any applications. Here, we show that non-magnetic Fullerene can obtain non-negligible magnetic moment at the interface of Fe(15 nm)/C 60 (40 nm) bilayer. This leads to substantial effect on both the magnetic domain structure as well as the magnetization reversal when compared to a single layer of Fe(15 nm). This is corroborated by the polarized neutron reflectivity (PNR) data which indicates presence of hybridization at the interface by the reduction of magnetic moment in Fe. Afterwards, upto 1.9 nm of C 60 near the interface exhibits magnetic moment. From the PNR measurements it was found that the magnetic C 60 layer prefers to be aligned anti-parallel with the Fe layer at the remanant state. The later observation has been confirmed by domain imaging via magneto-optic Kerr microscopy.

  14. Spin states of reduced fullerenes (C60 and C120O) by CW and pulsed EPR

    International Nuclear Information System (INIS)

    Boas, J.F.; Drew, S.C.; Pilbrow, J.R.; Boyd, P.D.W.; Paul, P.; Reed, C.A.; Sun, D.

    2003-01-01

    Full text: The ESTN (Electron Spin Transient Nutation) EPR (Electron Paramagnetic Resonance) experiments reported at Wagga 2002 showed that the spin states of the reduced fullerenes C 120 O (2-), C 120 O (3-) and C 120 O (4-) were S = 1, S = 1/2 and S = 1 respectively. Further experiments using CW (Continuous Wave) EPR have confirmed the results of Paul et al. and have now shown that these states are the ground states of these anions. In the case of C 60 (3-), the recent CW and ESTN EPR experiments have shown that the electronic ground state of this anion is S = 1/2. The observation of ground states of low multiplicity for these anions is contrary to expectations based on MO calculations and the application of Hund's rules. A series of CW EPR experiments on C 60 (3-) have shown that some previous results may need to be re-interpreted. This arises from the delineation of the effects of microwave power, modulation amplitude and frequency, sample temperature and freezing rate on the EPR spectrum which is the combination of a broad line, attributed to C 60 (3-), and a 'spike' attributed to C 120 O impurities and other oxygen related species. Our results cast doubt on the existence of Jahn-Teller effects at low temperatures and of a low-lying spin quartet excited state

  15. Target Plate Material Influence on Fullerene-C60 Laser Desorption/Ionization Efficiency

    Science.gov (United States)

    Zeegers, Guido P.; Günthardt, Barbara F.; Zenobi, Renato

    2016-04-01

    Systematic laser desorption/ionization (LDI) experiments of fullerene-C60 on a wide range of target plate materials were conducted to gain insight into the initial ion formation in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The positive and negative ion signal intensities of precursor, fragment, and cluster ions were monitored, varying both the laser fluence (0-3.53 Jcm-2) and the ion extraction delay time (0-950 ns). The resulting species-specific ion signal intensities are an indication for the ionization mechanisms that contribute to LDI and the time frames in which they operate, providing insight in the (MA)LDI primary ionization. An increasing electrical resistivity of the target plate material increases the fullerene-C60 precursor and fragment anion signal intensity. Inconel 625 and Ti90/Al6/V4, both highly electrically resistive, provide the highest anion signal intensities, exceeding the cation signal intensity by a factor ~1.4 for the latter. We present a mechanism based on transient electrical field strength reduction to explain this trend. Fullerene-C60 cluster anion formation is negligible, which could be due to the high extraction potential. Cluster cations, however, are readily formed, although for high laser fluences, the preferred channel is formation of precursor and fragment cations. Ion signal intensity depends greatly on the choice of substrate material, and careful substrate selection could, therefore, allow for more sensitive (MA)LDI measurements.

  16. Inner-shell near-threshold photoionization of A-C60 endohedral atoms

    International Nuclear Information System (INIS)

    Baltenkov, Arkadiy S.; Dolmatov, Valery K.; Manson, Steven T.

    2002-01-01

    Photoelectron angular distributions and total photoionization cross sections of near-threshold 1s photoionization of Li from the oriented-in-space endohedral Li-C 60 fullerene are investigated within the framework of our recently developed photoionization theory of multicenter formations. Both at-the-center and off-the-center endohedral Li are considered, and off-the-center effects are shown to be of extreme importance, in contrast to the conventional wisdom. Multiple-scattering effects on the outgoing photoelectron are included and found to influence the photoionization spectra strongly, e.g., decreasing the cross section by more than an order of magnitude in certain cases, as compared to the situation when such effects are neglected. Diffraction resonances in the photoionization cross section of the endohedral Li atom are found as a result of the multicenter nature of the C 60 surrounding cage, and these are compared with the results of other empirical and ab initio theories. Since there is nothing particularly special about Li 1s with respect to photoionization, the trends uncovered in this paper should qualitatively apply to near-threshold inner-shell ns photoionization spectra of virtually any endohedral atom A from any A-C 60 endohedral fullerene formation

  17. Quantitative FT-IR Analysis for Chondritic Meteorites: Search for C_60 in Meteorites

    Directory of Open Access Journals (Sweden)

    Chunglee Kim

    1998-06-01

    Full Text Available Infrared absorption spectra of 9 bulk samples and 3 acid residues of meteorites were obtained in the mid-infrared region (4000 ~ 400 cm^(-1. From the known composition of meteorites studied, the possible absorption modes were investigated. Most bands of bulk samples occur in the region below 1200 cm^(-1 and they are due to metallic oxides and silicates. The spectra of each group can be distinguished by its own characteristic bands. Acid residues show very distinct features from their bulk samples, and absorption bands due to organic compounds are not evident in their spectra. Quantitative analyses for two carbonaceous (Allende CV3 and Murchison CM2 and one ordinary (Carraweena L3.9 chondrites were performed for the presence of fullerene (C_60 in the meteorites. We calculated the concentration of C_60 in the acid residues by curvefitting the spectra with Gaussian functions. The upper limit of C_60 concentration in these meteorites appears to be less than an order of a few hundred ppm.

  18. Effect of Orbital Hybridization on Spin-Polarized Tunneling across Co/C60 Interfaces.

    Science.gov (United States)

    Wang, Kai; Strambini, Elia; Sanderink, Johnny G M; Bolhuis, Thijs; van der Wiel, Wilfred G; de Jong, Michel P

    2016-10-26

    The interaction between ferromagnetic surfaces and organic semiconductors leads to the formation of hybrid interfacial states. As a consequence, the local magnetic moment is altered, a hybrid interfacial density of states (DOS) is formed, and spin-dependent shifts of energy levels occur. Here, we show that this hybridization affects spin transport across the interface significantly. We report spin-dependent electronic transport measurements for tunnel junctions comprising C 60 molecular thin films grown on top of face-centered-cubic (fcc) epitaxial Co electrodes, an AlO x tunnel barrier, and an Al counter electrode. Since only one ferromagnetic electrode (Co) is present, spin-polarized transport is due to tunneling anisotropic magnetoresistance (TAMR). An in-plane TAMR ratio of approximately 0.7% has been measured at 5 K under application of a magnetic field of 800 mT. The magnetic switching behavior shows some remarkable features, which are attributed to the rotation of interfacial magnetic moments. This behavior can be ascribed to the magnetic coupling between the Co thin films and the newly formed Co/C 60 hybridized interfacial states. Using the Tedrow-Meservey technique, the tunnel spin polarization of the Co/C 60 interface was found to be 43%.

  19. Positron annihilation study of graphite, glassy carbon and C60/C70 fullerene

    International Nuclear Information System (INIS)

    Hasegawa, Masayuki; Kajino, Masahiro; Yamaguchi, Sadae; Iwata, Tadao; Kuramoto, Eiichi; Takenaka, Minoru.

    1992-01-01

    ACAR (Angular Correlation of Annihilation Radiation) and positron lifetime measurements have been made on, HOPG (Highly Oriented Pyrolytic Graphite), isotropic fine-grained graphite, glassy carbons and C 60 /C 70 powder. HOPG showed marked bimodality along the c-axis and anisotropy in ACAR momentum distribution, which stem from characteristic annihilation between 'interlayer' positrons and π-electrons in graphite. ACAR curves of the isotropic graphite and glassy carbons are even narrower than that of HOPG perpendicular to the c-axis. Positron lifetime of 420 and 390 - 480 psec, much longer than that of 221 psec in HOPG, were observed for the isotropic graphite and glassy carbons respectively, which are due to positron trapping in structural voids in them. Positron lifetime and ACAR width (FWHM) can be well correlated to void sizes (1.7 to 5.0 nm) of glassy carbons which have been determined by small angle neutron (SAN) scattering measurements. ACAR curves and positron lifetime of C 60 /C 70 powder agree well with those of glassy carbons. This shows that positron wave functions extend, as in the voids of glassy carbons, much wider than open spaces of the octahedral interstices of the face-centered cubic (FCC) structure of C 60 crystal and strongly suggests positron trapping in the 'soccer ball' vacancy. Possible positron states in the carbon materials are discussed with a simple model of void volume-trapping. Preliminary results on neutron irradiation damage in HOPG are also presented. (author)

  20. Charge Transport in C60-Based Dumbbell-type Molecules: Mechanically Induced Switching between Two Distinct Conductance States

    Czech Academy of Sciences Publication Activity Database

    Moreno-Garcia, P.; La Rosa, A.; Kolivoška, Viliam; Bermejo, D.; Hong, W.; Yoshida, K.; Baghernejad, M.; Filippone, S.; Broekmann, P.; Wandlowski, T.; Martin, N.

    2015-01-01

    Roč. 137, č. 6 (2015), s. 2318-2327 ISSN 0002-7863 R&D Projects: GA ČR(CZ) GA14-05180S Institutional support: RVO:61388955 Keywords : Atomic force microscopy * Electron tunneling * Fullerenes Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 13.038, year: 2015

  1. Time-resolved x-ray diffraction measurement of C60 under high pressure and temperature using synchrotron radiation

    International Nuclear Information System (INIS)

    Horikawa, T; Suito, K; Kobayashi, M; Onodera, A

    2002-01-01

    C 60 has been studied by means of time-resolved x-ray diffraction measurements using synchrotron radiation. Diffraction patterns were recorded at intervals of 1-10 min for samples under high pressure (12.5 and 14.3 GPa) and high temperature (up to 800 deg. C) for, at the longest, 3 h. Time, pressure, and temperature dependences of the C 60 structure are presented and the relevance to the hardness of materials derived from C 60 is discussed

  2. An experimental study on pool boiling characteristics of carbon nano tube (CNT) and fullerene (C-60) nanofluids

    International Nuclear Information System (INIS)

    Ai, Melani

    2009-02-01

    In recent years, it was found that pool boiling critical heat flux (CHF) increases in nanofluids. The CHF conditions are important for safe and economic design of many heat transfer units including nuclear reactor. In this study, our objective is to evaluate the impact of Carbone Nano Tubes (Singlewalled CNTs and Multiwalled CNTs) and Fullerene (C-60) nanofluids at different particle concentration on pool boiling critical heat flux experimentally at saturated conditions. Multiwalled CNT and fullerene (C-60) added in the pure water at three volume concentrations (0.01%, 0.001%, and 0.0001%). Singlewalled CNT nanoparticles added in the pure water at two volume concentrations (0.0005%, and 0.0001%). For the dispersion of nanoparticles in pure water, several treatments were performed. Multiwalled CNTs and Fullerene (C-60) prepared using acid treatment, meanwhile two treatment are using for Singlewalled CNTs: (1)Singlewalled CNTs prepared using polymer treatment, (2)Singlewalled CNTs prepared using pre polymerization of micelle treatment. The zeta potential of CNTs and Fullerene nanofluids were in the range of 13-71 mV. The zeta potential of nanofluids was constant for more than one month. It concludes that the treatment has been succeeded produces water dispersible CNTs and Fullerene nanofluids with good stability. The critical heat flux (CHFs) of the solution is enhanced greatly for all nanofluids. Enhanced (∼167.9%) CHF was observed for solutions with Multiwalled CNT nanoparticles with concentration 0.01 vol%. Enhanced (∼109.4%) CHF was observed for solutions with Singlewalled CNT nanoparticles with concentration 0.0005 vol%. Enhanced (∼108.9%) CHF was observed for solutions with Fullerene nanoparticles with concentration 0.01 vol%. The pool boiling Heat Transfer Coefficient (HTCs) of the CNTs nanofluids are lower than those of pure water in the entire nucleate boiling regime. On the other hand, the pool boiling HTCs of Fullerene nanofluids are higher than

  3. Mono- and polyadducts of C60 with anthracenes by Diels-Alder-reactions

    International Nuclear Information System (INIS)

    Duarte-Ruiz, A.

    2000-09-01

    This work describes the synthesis and characterization of seven new mono-adducts of 9-methylanthracene, 9,10-dimethylanthracene, 9-bromoanthracene. 2,3,6,7-tetramethylanthracene, 1-methylanthracene, 2,6-di-tert-butylanthracen, as well as 2-methylanthracene to fullerene C60 in solution at r.t. by means of [4+2] Diels-Alder reactions. It could be shown that the mono-adducts with 9-methylanthracene, 9,10-dimethylanthracene, and 1-methylanthracene form the corresponding antipodal bis-adduct 'trans-1' on heating the solid to 180 o C. Furthermore the functionalization of fullerene C60 anthracene mono-adduct (C60C14H10) with anthracene through [4+2] Diels-Alder reactions was investigated which made it possible to separate and to characterize the five possible bis-adducts ('trans-1', 'trans-2', 'trans-3', 'trans-4', and 'e') that can form when the second anthracene adds either 'trans' to the opposite hemisphere (compared to the first addition of anthracene) or to an equatorial position. An exact identification of the bis-adducts 'trans-2' and 'trans-4' could only be acquired with spectroscopic methods, fortunately the bis-adducts 'trans-4', 'trans-3', and 'e' could also be examined by x-ray, thus all five could be fully characterized. No bis-adducts on the same hemisphere ('cis') were found. UV/VIS-spectra of the bis-adducts opened up the possibility to identify other [4+2] Diels-Alder products in the future. It has been noticed that the eluation sequence of the bis-adducts ('trans-1' before 'trans-2' before 'trans-4' before 'trans-3' before 'e') doesn't strictly correlate with the dipole moments. Furthermore six new tris-adducts ('t4t4t2', 't3t3t3', 't3t3t4', 'et3t2', 'et3t4', and 'eee') and one tetra-adduct ('eeet3') were separated and characterized. The tris-adduct 't3t3t3' was additionally characterized by x-ray which showed that the crystal contains only one enatiomer. All bis- and tris-adducts form the antipodal bis-adduct 'trans-1' on heating to 180 o C for 10 min

  4. Confirming a predicted selection rule in inelastic neutron scattering spectroscopy: the quantum translator-rotator H2 entrapped inside C60.

    Science.gov (United States)

    Xu, Minzhong; Jiménez-Ruiz, Mónica; Johnson, Mark R; Rols, Stéphane; Ye, Shufeng; Carravetta, Marina; Denning, Mark S; Lei, Xuegong; Bačić, Zlatko; Horsewill, Anthony J

    2014-09-19

    We report an inelastic neutron scattering (INS) study of a H2 molecule encapsulated inside the fullerene C60 which confirms the recently predicted selection rule, the first to be established for the INS spectroscopy of aperiodic, discrete molecular compounds. Several transitions from the ground state of para-H2 to certain excited translation-rotation states, forbidden according to the selection rule, are systematically absent from the INS spectra, thus validating the selection rule with a high degree of confidence. Its confirmation sets a precedent, as it runs counter to the widely held view that the INS spectroscopy of molecular compounds is not subject to any selection rules.

  5. Multiscale Simulation and Modeling of Multilayer Heteroepitactic Growth of C60 on Pentacene.

    Science.gov (United States)

    Acevedo, Yaset M; Cantrell, Rebecca A; Berard, Philip G; Koch, Donald L; Clancy, Paulette

    2016-03-29

    We apply multiscale methods to describe the strained growth of multiple layers of C60 on a thin film of pentacene. We study this growth in the presence of a monolayer pentacene step to compare our simulations to recent experimental studies by Breuer and Witte of submonolayer growth in the presence of monolayer steps. The molecular-level details of this organic semiconductor interface have ramifications on the macroscale structural and electronic behavior of this system and allow us to describe several unexplained experimental observations for this system. The growth of a C60 thin film on a pentacene surface is complicated by the differing crystal habits of the two component species, leading to heteroepitactical growth. In order to probe this growth, we use three computational methods that offer different approaches to coarse-graining the system and differing degrees of computational efficiency. We present a new, efficient reaction-diffusion continuum model for 2D systems whose results compare well with mesoscale kinetic Monte Carlo (KMC) results for submonolayer growth. KMC extends our ability to simulate multiple layers but requires a library of predefined rates for event transitions. Coarse-grained molecular dynamics (CGMD) circumvents KMC's need for predefined lattices, allowing defects and grain boundaries to provide a more realistic thin film morphology. For multilayer growth, in this particularly suitable candidate for coarse-graining, CGMD is a preferable approach to KMC. Combining the results from these three methods, we show that the lattice strain induced by heteroepitactical growth promotes 3D growth and the creation of defects in the first monolayer. The CGMD results are consistent with experimental results on the same system by Conrad et al. and by Breuer and Witte in which C60 aggregates change from a 2D structure at low temperature to 3D clusters along the pentacene step edges at higher temperatures.

  6. Probing photoelectron multiple interferences via Fourier spectroscopy in energetic photoionization of Xe-C60

    International Nuclear Information System (INIS)

    Potter, Andrea; McCune, Matthew A.; De, Ruma; Chakraborty, Himadri S.; Madjet, Mohamed E.

    2010-01-01

    Considering the photoionization of the Xe-C 60 endohedral compound, we study in detail the ionization cross sections of various levels of the system at energies higher than the plasmon resonance region. Five classes of single-electron levels are identified depending on their spectral character. Each class engenders distinct oscillations in the cross section, emerging from the interference between active ionization modes specific to that class. Analysis of the cross sections based on their Fourier transforms unravels oscillation frequencies that carry unique fingerprints of the emitting level.

  7. Comparative study of pressure-induced polymerization in C60 nanorods and single crystals

    International Nuclear Information System (INIS)

    Hou Yuanyuan; Liu Bingbing; Wang Lin; Yu Shidan; Yao Mingguang; Chen Ao; Liu Dedi; Zou Yonggang; Li Zepeng; Zou Bo; Cui Tian; Zou Guangtian; Iwasiewicz-Wabnig, Agnieszka; Sundqvist, Bertil

    2007-01-01

    In this paper, we report a comparative study of pressure-induced polymerization in C 60 nanorods and bulk single crystals, treated simultaneously under various pressures and temperatures in the same experiment. For both materials, orthorhombic, tetragonal and rhombohedral phases have been produced under high pressure and high temperature. The structures have been identified and compared between the two sample types by Raman and photoluminescence spectroscopy. There are differences between the Raman and photoluminescence spectra from the two types of materials for all polymeric phases, but especially for the tetragonal phase. From the comparison between nanorods and bulk samples, we tentatively assign photoluminescence peaks for various polymeric phases

  8. Modification of C60/C70+Pd film structure under electric field influence during electron emission

    International Nuclear Information System (INIS)

    Czerwosz, E.; Dluzewski, P.; Kozlowski, M.

    2001-01-01

    We investigated the modification of structure of C 60 /C 70 +Pd films during cold electron emission from these films. Films were obtained by vacuum thermal deposition from two sources and were characterised before and after electron emission measurements by transmission electron microscopy and electron diffraction. Films were composed of nanocrystalline Pd objects dispersed in carbon/fullerenes matrix. I-V characteristics for electron emission were obtained in diode geometry with additionally applied voltage along the film surface. The modification of film structure occurred under applied electric field and the grouping of Pd nano crystals into bigger objects was observed

  9. Search for the form of fullerene C60 in aqueous medium

    Czech Academy of Sciences Publication Activity Database

    Pospíšil, Lubomír; Gál, Miroslav; Hromadová, Magdaléna; Kocábová, Jana; Kolivoška, Viliam; Cvačka, Josef; Nováková, Kateřina; Kavan, Ladislav; Zukalová, Markéta; Dunsch, L.

    2010-01-01

    Roč. 12, č. 42 (2010), s. 14095-14101 ISSN 1463-9076 R&D Projects: GA ČR GA203/09/0705; GA ČR GP203/09/P502; GA AV ČR IAA400400804; GA AV ČR KAN200100801; GA MŠk OC 140; GA MŠk LC510 Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z40550506 Keywords : fullerene C60 * electrochemical measurements * electrochemistry Subject RIV: CG - Electrochemistry Impact factor: 3.454, year: 2010

  10. Photochemical reduction of water-soluble C60 derivatives (EPR study)

    International Nuclear Information System (INIS)

    Brezova, V.; Stasko, A.; Dvoranova, D.; Asmus, K.D.; Guldi, D.M.

    1999-01-01

    The photochemical reduction of three bis-functionalized C 60 derivatives resulted in the formation of a single radical product, characterized by relatively narrow EPR line (g M = 2.0007, pp < 0.02 mT). In the irradiated aqueous solutions containing L-ascorbic acid, in the addition to the EPR line related to bis-adduct mono-anion, also 6-line EPR spectrum of ascorbyl radical was observed. Consequently, the photoinduced formation of ascorbyl radical was attributed to the intermolecular quenching of fullerenes excited states. (authors)

  11. In situ x-ray diffraction studies of three-dimensional C60 polymers

    International Nuclear Information System (INIS)

    Wood, R A; Lewis, M H; Bennington, S M; Cain, M G; Kitamura, N; Fukumi, A K

    2002-01-01

    In situ investigations into the P/T field of C 60 fullerene were performed using energy-dispersive x-ray diffraction techniques. Isobars were obtained at 11 and 9 GPa accompanied by isotherms at 750 and 800 K with pressure reaching 13 GPa. The P/T history and pressure isotropy were investigated with the aim of optimizing conditions for 3D polymer formation. Confirmation of the formation of 3D polymers was performed in situ; however, the reclaimed sample did not exhibit the expected high hardness value, due to depolymerization on pressure release. Isotropy in the pressure field promoted formation and retention of the face-centred-cubic structure

  12. High-pressure effects in hydrofullerene C60H36 studied by Raman spectroscopy

    International Nuclear Information System (INIS)

    Meletov, K.P.; Rossijskaya Akademiya Nauk, Chernogolovka; Tsilika, I.; Assimopoulos, S.; Kourouklis, G.A.; Ves, S.; Bashkin, I.O.; Kulakov, V.I.; Khasanov, S.S.

    2001-01-01

    The effect of hydrostatic pressure on the Raman spectrum of hydrofullerene C 60 H 36 , at room temperature has been investigated up to 12 GPa. The samples were synthesized by means of high-pressure hydrogenation. The pressure dependence of the phonon frequencies exhibits two reversible changes one at ∝0.6 GPa and another one at ∝6 GPa. The first may be probably related to a phase transition from the initial orientationally disordered bcc structure to an orientationally ordered one. The second one, at ∝6 GPa, is probably driven by pressure-induced bonding of hydrogen to a carbon atom of a neighboring hydrofullerene cage. (orig.)

  13. Synthesis of C60(OH)18-20 in aqueous alkaline solution under O2-atmosphere

    International Nuclear Information System (INIS)

    Alves, Gustavo Catao; Ladeira, Luiz Orlando; Righi, Ariete; Krambrock, Klaus; Pinheiro, Mauricio Veloso B.; Calado, Hallen Daniel; Gil, Rossimiriam Pereira de Freitas

    2006-01-01

    In this work we report on an alternative synthesis of water-soluble fullerenes known as fullerols, aiming for biomedical applications. The synthesis is based on a process in which polyethylene glycol (PEG400) is used as phase-transfer catalyst between fullerene/benzene and aqueous NaOH solutions. The polyhydroxylation of the fullerenes occurs in the NaOH solution under a continuous flow of O 2 to enhance the reaction yield. The resulting compound was characterized with infrared spectroscopy, nuclear magnetic resonance, thermo-gravimetric analysis and optical absorption. The formation of C 60 (OH) 18-20 in high yields was confirmed. (author)

  14. In Silico Olefin Metathesis with Ru-Based Catalysts Containing N-Heterocyclic Carbenes Bearing C60Fullerenes

    KAUST Repository

    Martínez, Juan Pablo

    2016-04-10

    Density functional theory calculations have been used to explore the potential of Ru-based complexes with 1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene (SIMes) ligand backbone (A) being modified in silico by the insertion of a C60 molecule (B and C), as olefin metathesis catalysts. To this end, we investigated the olefin metathesis reaction catalyzed by complexes A, B, and C using ethylene as the substrate, focusing mainly on the thermodynamic stability of all possible reaction intermediates. Our results suggest that complex B bearing an electron-withdrawing N-heterocyclic carbene improves the performance of unannulated complex A. The efficiency of complex B is only surpassed by complex A when the backbone of the N-heterocyclic carbene of complex A is substituted by two amino groups. The particular performance of complexes B and C has to be attributed to electronic factors, that is, the electronic-donating capacity of modified SIMes ligand rather than steric effects, because the latter are predicted to be almost identical for complexes B and C when compared to those of A. Overall, this study indicates that such Ru-based complexes B and C might have the potential to be effective olefin metathesis catalysts. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. In Silico Olefin Metathesis with Ru-Based Catalysts Containing N-Heterocyclic Carbenes Bearing C60Fullerenes

    KAUST Repository

    Martí nez, Juan Pablo; Vummaleti, Sai V. C.; Falivene, Laura; Nolan, Steven P.; Cavallo, Luigi; Solà , Miquel; Poater, Albert

    2016-01-01

    Density functional theory calculations have been used to explore the potential of Ru-based complexes with 1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene (SIMes) ligand backbone (A) being modified in silico by the insertion of a C60 molecule (B and C), as olefin metathesis catalysts. To this end, we investigated the olefin metathesis reaction catalyzed by complexes A, B, and C using ethylene as the substrate, focusing mainly on the thermodynamic stability of all possible reaction intermediates. Our results suggest that complex B bearing an electron-withdrawing N-heterocyclic carbene improves the performance of unannulated complex A. The efficiency of complex B is only surpassed by complex A when the backbone of the N-heterocyclic carbene of complex A is substituted by two amino groups. The particular performance of complexes B and C has to be attributed to electronic factors, that is, the electronic-donating capacity of modified SIMes ligand rather than steric effects, because the latter are predicted to be almost identical for complexes B and C when compared to those of A. Overall, this study indicates that such Ru-based complexes B and C might have the potential to be effective olefin metathesis catalysts. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Structural defects and epitaxial rotation of C-60 and C-70(111) films on GeS(001)

    DEFF Research Database (Denmark)

    Bernaerts, D.; Van Tendeloo, G.; Amelinckx, S.

    1996-01-01

    A transmission electron microscopy study of epitaxial C60 and C70 films grown on a GeS (001) surface is presented. The relationship between the orientation of the substrate and the films and structural defects in the films, such as grain boundaries, unknown in bulk C60 and C70 crystals, are studied...

  17. Highly selective reactions of C(60)Cl(6) with thiols for the synthesis of functionalized [60]fullerene derivatives

    OpenAIRE

    Khakina, Ekaterina A; Yurkova, Anastasiya A; Peregudov, Alexander S; Troyanov, Sergey I; Trush, Vyacheslav V; Vovk, Andrey I; Mumyatov, Alexander V; Martynenko, Vyacheslav M; Balzarini, Jan; Troshin, Pavel A

    2012-01-01

    Chlorofullerene C(60)Cl(6) undergoes highly selective reactions with thiols forming compounds C(60)[SR](5)H with high yields. These reactions open up straightforward synthetic routes to many functionalized fullerene derivatives, e.g. water-soluble compounds showing interesting biological activities.

  18. In silico properties characterization of water-soluble γ-cyclodextrin bi-capped C60 complex

    DEFF Research Database (Denmark)

    Cao, Ruyin; Wu, Shanshan

    2015-01-01

    Cyclodextrin-related host-guest encapsulation is pivotal to modulate the solubility of C60, thereby promoting its potential therapeutic applications. Here we present a computational study on γ-cyclodextrin bi-capped C60 complex, probing characteristics for all the possible stoichiometry in aqueou...

  19. A Journey along the Extruder with Polystyrene : C60 Nanocomposites: Convergence of Feeding Formulations into a Similar Nanomorphology

    NARCIS (Netherlands)

    Gaspar, Hugo; Teixeira, Paulo; Santos, Raquel; Fernandes, Liliana; Hilliou, Loic; Weir, Michael P.; Parnell, Andrew J.; Abrams, Kerry J.; Hill, Christopher J.; Bouwman, W.G.; Parnell, S.R.; King, Stephen M.; Clarke, Nigel; Covas, Jose A.; Bernardo, Gabriel

    2017-01-01

    We investigated the effect of the feeding formulation (premixed powders of pure components versus solvent-blended mixture) of polystyrene–C60 composites on the dispersion and reagglomeration phenomena developing along the barrel of a twin-screw extruder. The dispersion of C60 in the PS matrix is

  20. Facile preparation of amine and amino acid adducts of [60]fullerene using chlorofullerene C60Cl6 as a precursor.

    Science.gov (United States)

    Kornev, Alexey B; Khakina, Ekaterina A; Troyanov, Sergey I; Kushch, Alla A; Peregudov, Alexander; Vasilchenko, Alexey; Deryabin, Dmitry G; Martynenko, Vyacheslav M; Troshin, Pavel A

    2012-06-04

    We report a general synthetic approach to the preparation of highly functionalized amine and amino acid derivatives of [60]fullerene starting from readily available chlorofullerene C(60)Cl(6). The synthesized water-soluble amino acid derivative of C(60) demonstrated pronounced antiviral activity, while the cationic amine-based compound showed strong antibacterial action in vitro.

  1. Electronic properties of Mn-phthalocyanine–C60 bulk heterojunctions: Combining photoemission and electron energy-loss spectroscopy

    International Nuclear Information System (INIS)

    Roth, Friedrich; Herzig, Melanie; Knupfer, Martin; Lupulescu, Cosmin; Darlatt, Erik; Gottwald, Alexander; Eberhardt, Wolfgang

    2015-01-01

    The electronic properties of co-evaporated mixtures (blends) of manganese phthalocyanine and the fullerene C 60 (MnPc:C 60 ) have been studied as a function of the concentration of the two constituents using two supplementary electron spectroscopic methods, photoemission spectroscopy (PES) and electron energy-loss spectroscopy (EELS) in transmission. Our PES measurements provide a detailed picture of the electronic structure measured with different excitation energies as well as different mixing ratios between MnPc and C 60 . Besides a relative energy shift, the occupied electronic states of the two materials remain essentially unchanged. The observed energy level alignment is different compared to that of the related CuPc:C 60 bulk heterojunction. Moreover, the results from our EELS investigations show that, despite the rather small interface interaction, the MnPc related electronic excitation spectrum changes significantly by admixing C 60 to MnPc thin films

  2. TEMPO functionalized C60 fullerene deposited on gold surface for catalytic oxidation of selected alcohols

    International Nuclear Information System (INIS)

    Piotrowski, Piotr; Pawłowska, Joanna; Sadło, Jarosław Grzegorz; Bilewicz, Renata; Kaim, Andrzej

    2017-01-01

    C 60 TEMPO 10 catalytic system linked to a microspherical gold support through a covalent S-Au bond was developed. The C 60 TEMPO 10 @Au composite catalyst had a particle size of 0.5–0.8 μm and was covered with the fullerenes derivative of 2.3 nm diameter bearing ten nitroxyl groups; the organic film showed up to 50 nm thickness. The catalytic composite allowed for the oxidation under mild conditions of various primary and secondary alcohols to the corresponding aldehyde and ketone analogues with efficiencies as high as 79–98%, thus giving values typical for homogeneous catalysis, while retaining at the same time all the advantages of heterogeneous catalysis, e.g., easy separation by filtration from the reaction mixture. The catalytic activity of the resulting system was studied by means of high pressure liquid chromatography. A redox mechanism was proposed for the process. In the catalytic cycle of the oxidation process, the TEMPO moiety was continuously regenerated in situ with an applied primary oxidant, for example, O 2 /Fe 3+ system. The new intermediate composite components and the final catalyst were characterized by various spectroscopic methods and thermogravimetry.

  3. The strength of electron electron correlation in Cs3C60

    Science.gov (United States)

    Baldassarre, L.; Perucchi, A.; Mitrano, M.; Nicoletti, D.; Marini, C.; Pontiroli, D.; Mazzani, M.; Aramini, M.; Riccó, M.; Giovannetti, G.; Capone, M.; Lupi, S.

    2015-10-01

    Cs3C60 is an antiferromagnetic insulator that under pressure (P) becomes metallic and superconducting below Tc = 38 K. The superconducting dome present in the T - P phase diagram close to a magnetic state reminds what found in superconducting cuprates and pnictides, strongly suggesting that superconductivity is not of the conventional Bardeen-Cooper-Schrieffer (BCS) type We investigate the insulator to metal transition induced by pressure in Cs3C60 by means of infrared spectroscopy supplemented by Dynamical Mean-Field Theory calculations. The insulating compound is driven towards a metallic-like behaviour, while strong correlations survive in the investigated pressure range. The metallization process is accompanied by an enhancement of the Jahn-Teller effect. This shows that electronic correlations are crucial in determining the insulating behaviour at ambient pressure and the bad metallic nature for increasing pressure. On the other hand, the relevance of the Jahn-Teller coupling in the metallic state confirms that phonon coupling survives in the presence of strong correlations.

  4. Fullerene C60 hydroxylated with peracetic acid and its radioprotective effects tested in vivo

    International Nuclear Information System (INIS)

    Zemanova, Eva; Klouda, Karel

    2011-01-01

    A water-soluble C60 derivative (DF) was obtained by reacting C60 fullerene with peracetic acid followed by hydrolysis. The highest DF concentration achieved at room temperature and neutral pH was 443.2 mg/L. TEM and SEM observations and FTIR spectra were interpreted The possibility of DF application as a substance improving resistance to ionizing radiation (6X, linear accelerator, 10-70 Gry) was investigated in vivo using juvenile (2.5 months) Danio rerio without sex selection. A prolonged toxicity test gave evidence that an aqueous DF solution 147 mg/L is not toxic to this fish species in the long run. A radioprotective effect was demonstrated for a five-day exposure to this solution prior to irradiation. The survival times after irradiation with 10 to 70 Gy doses were up to 70% longer. The LD50 values for various times of survival roughly doubled. The effect is preventive rather than curative and is associated with the capability of fullerenes to eliminate free radicals and oxidants formed by radiolysis of water. (orig.)

  5. Characterization and photoconductivity study of well-defined C60 terminated poly(tert-butyl acrylate-b-styrene)

    International Nuclear Information System (INIS)

    Yang Dong; Li Lang; Wang Changchun

    2004-01-01

    Atom transfer radical polymerization (ATRP) catalyzed by N,N',N',N'',N''-pentamethyldiethylenetriamine (PMDETA)/CuBr was performed to synthesize poly (tert-butyl acrylate) (PtBA-Br) with predesigned molecular weight and narrow polydispersity. Using the PtBA-Br as macroinitiator, the PtBA-block-PS copolymer was prepared through ATRP. After terminated bromine atom was converted to end-functional azide group (P(tBA-b-St)-N 3 ), C 60 end-capped PtBA-PS block copolymers (P(tBA-b-St)-C 60 ) were synthesized by reacting C 60 with P(tBA-b-St)-N 3 . GPC characterizations showed that C 60 was chemically bonded to the end of P(tBA-b-St) chain and the products were mono-substituted. FT-IR, UV-Vis measurements confirmed that hydrolysis of P(tBA-b-St)-C 60 resulted in amphiphilic C 60 end-capped PAA-PS block copolymers. In additional, the photoconductivity of P(tBA-b-St)-C 60 was measured

  6. Solution and solid state NMR studies of the structure and dynamics of C60 and C70

    International Nuclear Information System (INIS)

    Johnson, R.D.; Yannoni, C.S.; Salem, J.; Meijer, G.; Bethune, D.S.

    1991-01-01

    This paper investigates the structure and dynamics of C 60 and C 70 with 13 C NMR spectroscopy. In solution, high-resolution spectra reveal that C 60 has a single resonance at 143 ppm, indicating a strained, aromatic system with high symmetry. This is strong evidence for a C 60 soccer ball geometry. A 2D NMR INADEQUATE experiment on 13 C-enriched C 70 reveals the bonding connectivity to be a linear string, in firm support of the proposed rugby ball structure with D 5h symmetry, and furnishes resonance assignments. Solid state NMR spectra of C 60 at ambient temperatures yield a narrow resonance, indicative of rapid molecular reorientation. Variable temperature T 1 measurements show that the rotational correlation time is ∼ 10 - 9 s at 230 K. At 77 K, this time increases to more than 1 ms, and the 13 C NMR spectrum of C 60 is a powder pattern due to chemical shift anisotropy (tensor components 220, 186, 40 ppm). At intermediate temperatures a narrow peak is superimposed on the powder pattern, suggesting a distribution of barriers to molecular motion in the sample, or the presence of an additional phase in the solid state. A Carr-Purcell dipolar experiment on C 60 in the solid state allows the first precise determination of the C 60 bond lengths: 1.45 and 1.40 Angstrom

  7. Impact of electron delocalization on the nature of the charge-transfer states in model pentacene/C60 Interfaces: A density functional theory study

    KAUST Repository

    Yang, Bing

    2014-12-04

    Electronic delocalization effects have been proposed to play a key role in photocurrent generation in organic photovoltaic devices. Here, we study the role of charge delocalization on the nature of the charge-transfer (CT) states in the case of model complexes consisting of several pentacene molecules and one fullerene (C60) molecule, which are representative of donor/acceptor heterojunctions. The energies of the CT states are examined by means of time-dependent density functional theory (TD-DFT) using the long-range-corrected functional, ωB97X, with an optimized range-separation parameter, ω. We provide a general description of how the nature of the CT states is impacted by molecular packing (i.e., interfacial donor/acceptor orientations), system size, and intermolecular interactions, features of importance in the understanding of the charge-separation mechanism.

  8. Absolute Charge Transfer and Fragmentation Cross Sections in He2+-C60 Collisions

    International Nuclear Information System (INIS)

    Rentenier, A.; Moretto-Capelle, P.; Bordenave-Montesquieu, D.; Bordenave-Montesquieu, A.; Ruiz, L. F.; Diaz-Tendero, S.; Alcami, M.; Martin, F.; Zarour, B.; Hanssen, J.; Hervieux, P.-A.; Politis, M. F.

    2008-01-01

    We have determined absolute charge transfer and fragmentation cross sections in He 2+ +C 60 collisions in the impact-energy range 0.1-250 keV by using a combined experimental and theoretical approach. We have found that the cross sections for the formation of He + and He 0 are comparable in magnitude, which cannot be explained by the sole contribution of pure single and double electron capture but also by contribution of transfer-ionization processes that are important even at low impact energies. The results show that multifragmentation is important only at impact energies larger than 40 keV; at lower energies, sequential C 2 evaporation is the dominant process

  9. Photo excitation and laser detachment of C60 − anions in a storage ring

    DEFF Research Database (Denmark)

    Støchkel, Kristian; Andersen, Jens Ulrik

    2013-01-01

    (REMPED) has been repeated both at room temperature and with the trap cooled to liquid nitrogen temperature. However, wavelength dependence of the overlap of the strongly focused laser beam with the ion beam introduces distortions of the absorption spectrum. We have therefore applied a new method......, combining the IR light with a slightly delayed, powerful UV pulse (266 nm). After absorption of three UV photons, the ions decay by delayed (thermal) electron emission, and time spectra are recorded for varying wavelength. The fraction of ions heated by absorption of a single IR photon is then extracted...... level, is much weaker in the new measurements and could be an H g vibrational sideband. Also earlier studies of direct laser detachment from C60 − in the storage ring ASTRID have been revisited, with ions cooled by liquid nitrogen in the ion trap. We confirm the previous measurement with a determination...

  10. Tandem white organic light-emitting diodes adopting a C60:rubrene charge generation layer

    International Nuclear Information System (INIS)

    Bi Wen-Tao; Wu Xiao-Ming; Hua Yu-Lin; Sun Jin-E; Xiao Zhi-Hui; Wang Li; Yin Shou-Gen

    2014-01-01

    Organic bulk heterojunction fullerence (C 60 ) doped 5, 6, 11, 12-tetraphenylnaphthacene (rubrene) as the high quality charge generation layer (CGL) with high transparency and superior charge generating capability for tandem organic light emitting diodes (OLEDs) is developed. This CGL shows excellent optical transparency about 90%, which can reduce the optical interference effect formed in tandem OLEDs. There is a stable white light emission including 468 nm and 500 nm peaks from the blue emitting layer and 620 nm peak from the red emitting layer in tandem white OLEDs. A high efficiency of about 17.4 cd/A and CIE coordinates of (0.40, 0.35) at 100 cd/m 2 and (0.36, 0.34) at 1000 cd/m 2 have been demonstrated by employing the developed CGL, respectively. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  11. Communication: The H2@C60 inelastic neutron scattering selection rule: Expanded and explained

    Science.gov (United States)

    Poirier, Bill

    2015-09-01

    Recently [M. Xu et al., J. Chem. Phys. 139, 064309 (2013)], an unexpected selection rule was discovered for the title system, contradicting the previously held belief that inelastic neutron scattering (INS) is not subject to any selection rules. Moreover, the newly predicted forbidden transitions, which emerge only in the context of coupled H2 translation-rotation (TR) dynamics, have been confirmed experimentally. However, a simple physical understanding, e.g., based on group theory, has been heretofore lacking. This is provided in the present paper, in which we (1) derive the correct symmetry group for the H2@C60 TR Hamiltonian and eigenstates; (2) complete the INS selection rule, and show that the set of forbidden transitions is actually much larger than previously believed; and (3) evaluate previous theoretical and experimental results, in light of the new findings.

  12. Theoretical analysis for the specific heat and thermal parameters of solid C60

    Science.gov (United States)

    Soto, J. R.; Calles, A.; Castro, J. J.

    1997-08-01

    We present the results of a theoretical analysis for the thermal parameters and phonon contribution to the specific heat in solid C60. The phonon contribution to the specific heat is calculated through the solution of the corresponding dynamical matrix, for different points in the Brillouin zone, and the construccion of the partial and generalized phonon density of states. The force constants are obtained from a first principle calculation, using a SCF Hartree-Fock wave function from the Gaussian 92 program. The thermal parameters reported are the effective temperatures and vibrational amplitudes as a function of temperature. Using this model we present a parametization scheme in order to reproduce the general behaviour of the experimental specific heat for these materials.

  13. Simulation of the channelling of ions from MeV C60 in crystalline solids

    International Nuclear Information System (INIS)

    Fetterman, A; Sinclair, L; Tanushev, N; Tombrello, T; Nardi, E

    2007-01-01

    Simulations were performed describing the motion and breakup of energetic C 60 ions interacting with crystalline targets. A hybrid algorithm was used that employs a binary collision model for the scattering of the carbon ions by the atoms of the solid, and molecular dynamics for the Coulomb interactions of the 60 carbon ions with one another. For the case of yttrium iron garnet (YIG), directions such as [1 1 0], [1 0 0], [0 1 0] and [0 0 1] demonstrate channelling for a large fraction of the C ions. For directions such as [1 1 1], [2 1 1] and [7 5 3] the trajectories show no more channelling than for random directions. The effects of tilt, shielding and wake-field interactions were investigated for YIG and α-quartz

  14. Biological effect of aqueous C60 aggregates on Scenedesmus obliquus revealed by transcriptomics and non-targeted metabolomics.

    Science.gov (United States)

    Du, Chunlei; Zhang, Bo; He, Yiliang; Hu, Chaoyang; Ng, Qin Xiang; Zhang, Hui; Ong, Choon Nam; ZhifenLin

    2017-02-15

    This work evaluated biological effect of nC 60 on Scenedesmus obliquus. The cells were exposed to various concentrations of nC 60 for 7days. Low-dose of nC 60 was found to have a minor growth inhibitory effect. The transcriptomics and metabolomics were integrated to examine intricate molecular and cellular effects of nC 60 on Scenedesmus obliquus. We found that Scenedesmus obliquus cells exposed to nC 60 had several significant alterations in cellular transcription and biochemical processes. During the 7-day exposure to nC 60 , 2234 and 2,448 unigenes were differentially expressed by 0.1mg/L and 1mg/L nC 60 -treated groups compared with the control, including 2085 or 2247 up-regulated genes and 149 or 201 down-regulated genes, respectively. We successfully identified 22 metabolites, including 6 significantly changed metabolites, such as sucrose, d-glucose, and malic acid. The citrate cycle (TCA cycle) (ko00020) was the main target of both differentially expressed genes and metabolic change. However, accumulation of sucrose (end-product) could have induced feedback inhibition of photosynthesis in Scenedesmus obliquus, explaining the slight growth inhibition observed. The results provided a mechanistic understanding of the growth inhibition of nC 60 toxicity. These genes and metabolites are useful biomarkers for future studies and offer new insights into the early detectable changes in Scenedesmus obliquus with nC 60 exposure. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Neuronal uptake and intracellular superoxide scavenging of a fullerene (C60)-poly(2-oxazoline)s nanoformulation

    KAUST Repository

    Tong, Jing

    2011-05-01

    Fullerene, the third allotrope of carbon, has been referred to as a "radical sponge" because of its powerful radical scavenging activities. However, the hydrophobicity and toxicity associated with fullerene limits its application as a therapeutic antioxidant. In the present study, we sought to overcome these limitations by generating water-soluble nanoformulations of fullerene (C(60)). Fullerene (C(60)) was formulated with poly(N-vinyl pyrrolidine) (PVP) or poly(2-alkyl-2-oxazoline)s (POx) homopolymer and random copolymer to form nano-complexes. These C(60)-polymer complexes were characterized by UV-vis spectroscopy, infrared spectroscopy (IR), dynamic light scattering (DLS), atomic force microscopy (AFM) and transmission electron microscopy (TEM). Cellular uptake and intracellular distribution of the selected formulations in catecholaminergic (CATH.a) neurons were examined by UV-vis spectroscopy, immunofluorescence and immunogold labeling. Electron paramagnetic resonance (EPR) spectroscopy was used to determine the ability of these C(60)-polymer complexes to scavenge superoxide. Their cytotoxicity was evaluated in three different cell lines. C(60)-POx and C(60)-PVP complexes exhibited similar physicochemical properties and antioxidant activities. C(60)-poly(2-ethyl-2-oxazoline) (PEtOx) complex, but not C(60)-PVP complex, were efficiently taken up by CATH.a neurons and attenuated the increase in intra-neuronal superoxide induced by angiotensin II (Ang II) stimulation. These results show that C(60)-POx complexes are non-toxic, neuronal cell permeable, superoxide scavenging antioxidants that might be promising candidates for the treatment of brain-related diseases associated with increased levels of superoxide.

  16. Extraction and HPLC- UV Analysis of C60, C70, and [6,6]-phenyl C61-butyric acid methyl ester in Synthetic and Natural Waters

    Science.gov (United States)

    Studies have shown that C60 fullerene can form stable colloidal suspensions in water that result in C60 aqueous concentrations many orders of magnitude above C60's aqueous solubility; however, quantitative methods for the analysis of C60 and other fullerenes in environmental medi...

  17. Jahn-Teller effect versus Hund's rule coupling in C60N-

    Science.gov (United States)

    Wehrli, S.; Sigrist, M.

    2007-09-01

    We propose variational states for the ground state and the low-energy collective rotator excitations in negatively charged C60N- ions (N=1,…,5) . The approach includes the linear electron-phonon coupling and the Coulomb interaction on the same level. The electron-phonon coupling is treated within the effective mode approximation which yields the linear t1u⊗Hg Jahn-Teller problem whereas the Coulomb interaction gives rise to Hund’s rule coupling for N=2,3,4 . The Hamiltonian has accidental SO(3) symmetry which allows an elegant formulation in terms of angular momenta. Trial states are constructed from coherent states and using projection operators onto angular momentum subspaces which results in good variational states for the complete parameter range. The evaluation of the corresponding energies is to a large extent analytical. We use the approach for a detailed analysis of the competition between Jahn-Teller effect and Hund’s rule coupling, which determines the spin state for N=2,3,4 . We calculate the low-spin-high-spin gap for N=2,3,4 as a function of the Hund’s rule coupling constant J . We find that the experimentally measured gaps suggest a coupling constant in the range J=60-80meV . Using a finite value for J , we recalculate the ground state energies of the C60N- ions and find that the Jahn-Teller energy gain is partly counterbalanced by the Hund’s rule coupling. In particular, the ground state energies for N=2,3,4 are almost equal.

  18. Enhanced performance of C60 N-type organic field-effect transistors using a pentacene passivation layer

    International Nuclear Information System (INIS)

    Liang Xiaoyu; Cheng Xiaoman; Du Boqun; Bai Xiao; Fan Jianfeng

    2013-01-01

    We investigated the properties of C 60 -based organic field-effect transistors (OFETs) with a pentacene passivation layer inserted between the C 60 active layer and the gate dielectric. After modification of the pentacene passivation layer, the performance of the devices was considerably improved compared to C 60 -based OFETs with only a PMMA dielectric. The peak field-effect mobility was up to 1.01 cm 2 /(V·s) and the on/off ratio shifted to 10 4 . This result indicates that using a pentacene passivation layer is an effective way to improve the performance of N-type OFETs. (semiconductor devices)

  19. Properties of K,Rb-intercalated C60 encapsulated inside carbon nanotubes called peapods derived from nuclear magnetic resonance

    KAUST Repository

    Mahfouz, Remi; Bouhrara, M.; Kim, Y.; Wå gberg, T.; Goze-Bac, C.; Abou-Hamad, Edy

    2015-01-01

    We present a detailed experimental study on how magnetic and electronic properties of Rb,K-intercalated C60 encapsulated inside carbon nanotubes called peapods can be derived from 13C nuclear magnetic resonance investigations. Ring currents do play

  20. Photoionization of Xe inside C60: Atom-fullerene hybridization, giant cross-section enhancement, and correlation confinement resonances

    International Nuclear Information System (INIS)

    Madjet, Mohamed E.; Renger, Thomas; Hopper, Dale E.; McCune, Matthew A.; Chakraborty, Himadri S.; Rost, Jan-M.; Manson, Steven T.

    2010-01-01

    A theoretical study of the subshell photoionization of the Xe atom endohedrally confined in C 60 is presented. Powerful hybridization of the Xe 5s state with the bottom edge of C 60 π band is found that induces strong structures in the 5s ionization, causing the cross section to differ significantly from earlier results that omit this hybridization. The hybridization also affects the angular distribution asymmetry parameter of Xe 5p ionization near the Cooper minimum. The 5p cross section, on the other hand, is greatly enhanced by borrowing considerable oscillator strength from the C 60 giant plasmon resonance via the atom-fullerene dynamical interchannel coupling. Beyond the C 60 plasmon energy range the atomic subshell cross sections display confinement-induced oscillations in which, over the large 4d shape resonance region, the dominant 4d oscillations induce their ''clones'' in all degenerate weaker channels known as correlation confinement resonances.

  1. Neuronal uptake and intracellular superoxide scavenging of a fullerene (C60)-poly(2-oxazoline)s nanoformulation

    KAUST Repository

    Tong, Jing; Zimmerman, Matthew C.; Li, Shumin; Yi, Xiang; Luxenhofer, Robert; Jordan, Rainer; Kabanov, Alexander V.

    2011-01-01

    and random copolymer to form nano-complexes. These C(60)-polymer complexes were characterized by UV-vis spectroscopy, infrared spectroscopy (IR), dynamic light scattering (DLS), atomic force microscopy (AFM) and transmission electron microscopy (TEM

  2. Dirac-Fock-Slater calculations on the geometric and electronic structure of neutral and multiply charged C60 fullerenes

    International Nuclear Information System (INIS)

    Bastug, T.; Kuerpick, P.; Meyer, J.; Sepp, W.; Fricke, B.; Rosen, A.

    1997-01-01

    Using a self-consistent relativistic molecular Dirac-Fock-Slater method we have determined the geometric structures and ionization energies of C 60 x t (x=0 endash 7). The lengths of the bonds for the pentagonal edge (single bonds) and the bonds shared by hexagonal rings (double bonds) are found to increase as a function of charge state with an expansion of the cage. The binding energy per atom of C 60 x t (x=0 endash 7) shows a quadratic dependence on the charge state of the C 60 cluster and an extrapolation to higher charge states reveals that C 60 x t should still be bound up to x=13. Charging of the clusters are analyzed using a classical capacitance model and compared with results from other calculations. Calculated ionization potentials are found to increase linearly with the charge while the available experimental data with comparatively big uncertainties indicate a small quadratic dependence. copyright 1997 The American Physical Society

  3. Oxidatively damaged DNA in rats exposed by oral gavage to C60 fullerenes and single-walled carbon nanotubes

    DEFF Research Database (Denmark)

    Folkmann, Janne K; Risom, Lotte; Jacobsen, Nicklas R

    2009-01-01

    BACKGROUND: C60 fullerenes and single-walled carbon nanotubes (SWCNT) are projected to be used in medicine and consumer products with potential human exposure. The hazardous effects of these particles are expected to involve oxidative stress with generation of oxidatively damaged DNA that might...... be the initiating event in the development of cancer. OBJECTIVE: In this study we investigated the effect of a single oral administration of C60 fullerenes and SWCNT. METHODS: We measured the level of oxidative damage to DNA as the premutagenic 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) in the colon mucosa...... of genotoxicity, whereas corn oil per se generated more genotoxicity than the particles. Although there was increased mRNA expression of 8-oxoguanine DNA glycosylase in the liver of C60 fullerene-treated rats, we found no significant increase in repair activity. CONCLUSIONS: Oral exposure to low doses of C60...

  4. Toxicity and bioaccumulation of xenobiotic organic compounds in the presence of aqueous suspensions of aggregates of nano-C60

    DEFF Research Database (Denmark)

    Baun, Anders; Sørensen, Sara Nørgaard; Rasmussen, R.F.

    2008-01-01

    The potential of C60-nanoparticles (Buckminster fullerenes) as contaminant carriers in aqueous systems was studied in a series of toxicity tests with algae (Pseudokirchneriella subcapitata) and crustaceans (Daphnia magna). Four common environmental contaminants (atrazine, methyl parathion, pentac...

  5. Impact of MoO3 interlayer on the energy level alignment of pentacene-C60 heterostructure.

    Science.gov (United States)

    Zou, Ye; Mao, Hongying; Meng, Qing; Zhu, Daoben

    2016-02-28

    Using in situ ultraviolet photoelectron spectroscopy, the electronic structure evolutions at the interface between pentacene and fullerene (C60), a classical organic donor-acceptor heterostructure in organic electronic devices, on indium-tin oxide (ITO) and MoO3 modified ITO substrates have been investigated. The insertion of a thin layer MoO3 has a significant impact on the interfacial energy level alignment of pentacene-C60 heterostructure. For the deposition of C60 on pentacene, the energy difference between the highest occupied molecular orbital of donor and the lowest unoccupied molecular orbital of acceptor (HOMO(D)-LUMO(A)) offset of C60/pentacene heterostructure increased from 0.86 eV to 1.54 eV after the insertion of a thin layer MoO3 on ITO. In the inverted heterostructrure where pentacene was deposited on C60, the HOMO(D)-LUMO(A) offset of pentacene/C60 heterostructure increased from 1.32 to 2.20 eV after MoO3 modification on ITO. The significant difference of HOMO(D)-LUMO(A) offset shows the feasibility to optimize organic electronic device performance through interfacial engineering approaches, such as the insertion of a thin layer high work function MoO3 films.

  6. Immunotoxicity of nanoparticles: a computational study suggests that CNTs and C60 fullerenes might be recognized as pathogens by Toll-like receptors

    Science.gov (United States)

    Turabekova, M.; Rasulev, B.; Theodore, M.; Jackman, J.; Leszczynska, D.; Leszczynski, J.

    2014-03-01

    Over the last decade, a great deal of attention has been devoted to study the inflammatory response upon exposure to multi/single-walled carbon nanotubes (CNTs) and different fullerene derivatives. In particular, carbon nanoparticles are reported to provoke substantial inflammation in alveolar and bronchial epithelial cells, epidermal keratinocytes, cultured monocyte-macrophage cells, etc. We suggest a hypothetical model providing the potential mechanistic explanation for immune and inflammatory responses observed upon exposure to carbon nanoparticles. Specifically, we performed a theoretical study to analyze CNT and C60 fullerene interactions with the available X-ray structures of Toll-like receptors (TLRs) homo- and hetero-dimer extracellular domains. This assumption was based on the fact that similar to the known TLR ligands both CNTs and fullerenes induce, in cells, the secretion of certain inflammatory protein mediators, such as interleukins and chemokines. These proteins are observed within inflammation downstream processes resulted from the ligand molecule dependent inhibition or activation of TLR-induced signal transduction. Our computational studies have shown that the internal hydrophobic pockets of some TLRs might be capable of binding small-sized carbon nanostructures (5,5 armchair SWCNTs containing 11 carbon atom layers and C60 fullerene). High binding scores and minor structural alterations induced in TLR ectodomains upon binding C60 and CNTs further supported our hypothesis. Additionally, the proposed hypothesis is strengthened by the indirect experimental findings indicating that CNTs and fullerenes induce an excessive expression of specific cytokines and chemokines (i.e. IL-8 and MCP1).Over the last decade, a great deal of attention has been devoted to study the inflammatory response upon exposure to multi/single-walled carbon nanotubes (CNTs) and different fullerene derivatives. In particular, carbon nanoparticles are reported to provoke

  7. In Silico Study of Spacer Arm Length Influence on Drug Vectorization by Fullerene C60

    Directory of Open Access Journals (Sweden)

    Haifa Khemir

    2015-01-01

    Full Text Available This work studies theoretically the effect of spacer arm lengths on the characteristics of a fullerene C60-based nanovector. The spacer arm is constituted of a carbon chain including a variable number of methylene groups (n = 2–11. To improve the ability of the fullerene carriage, two arms are presented simultaneously through a malonyl bridge. Then the evolution of selected physicochemical parameters is monitored as a function of the spacer arm length and the angle between the two arms. We show here that while the studied characteristics are almost independent of the spacer arm length or vary monotonically with it, the dipole moment and its orientation vary periodically with the parity of the number of carbon atoms. This periodicity is related to both modules and orientations of dipole moments of the spacer arms. In the field of chemical synthesis, these results highlight the importance of theoretical calculations for the optimization of operating conditions. In the field of drug discovery, they show that theoretical calculations of the chemical properties of a drug candidate can help predict its in vivo behaviour, notably its bioavailability and biodistribution, which are known to be tightly dependent of its polarity.

  8. AC electric field assisted orientational photorefractive effect in C60-doped nematic liquid crystal

    International Nuclear Information System (INIS)

    Sun Xiudong; Pei Yanbo; Yao Fengfeng; Zhang Jianlong; Hou Chunfeng

    2007-01-01

    Photorefractive gratings were produced in a C 60 -doped nematic liquid crystal cell under the application of two coherent beams and a nonbiased sinusoidal ac electric field. The beam coupling and diffraction of the ac electric field assisted gratings were studied systematically. A stable asymmetric energy transference was obtained. Diffraction was observed when the angle (between the normal of the cell and the bisector of the writing beams) was 0 0 , and the dependence of diffraction efficiency on the peak-to-peak value of the ac voltage was similar to that at an incidence angle of 45 0 , suggesting that the role of the ac field was to facilitate the charge separation, and the space-charge field (SCF) originated predominantly from the diffusion of the ac electric field assisted photo-induced carriers under the application of nonuniform illumination and an applied ac field. The grating was produced by director reorientation induced by the cooperation of the SCF and the applied ac electric field. A self-erasing phenomenon was observed in this cell. An explanation in terms of the movement of two kinds of carriers with opposite signs was proposed

  9. Zero-charged catanionic lamellar liquid crystals doped with fullerene C60 for potential applications in tribology.

    Science.gov (United States)

    Chen, Mengjun; Liu, Baoyong; Wang, Xiaolin; Fu, Yanxu; Hao, Jingcheng; Li, Hongguang

    2017-09-20

    The formation of lamellar liquid crystals (LLCs) has been demonstrated in a few salt-free catanionic surfactant systems and their properties have been well documented. However, examples of their combination with other materials are relatively rare. Herein, a salt-free zero-charged catanionic surfactant with low chain melting temperature was prepared by mixing equimolar tetradecyltrimethylammonium oxide (TTAOH) and oleic acid (OA) in water, and its concentration-dependent aggregate transition was investigated. In the dilute region (c TTAO ≤ 5 wt%), fluorescence microscopy observations revealed the formation of vesicles (the L αv phase). Further increasing c TTAO induced a transition from the L αv phase to LLCs via a region where vesicles and lamellae coexist. With ordered hydrophobic domains, the LLCs can be used as hosts for the doping of fullerene C 60 (refers to C 60 hereafter) with the highest C 60 /TTAO weight ratio of 0.04. The doping of C 60 effectively improves the viscoelasticity of the LLCs confirmed by rheological characterization while only slight modifications on their matrixes have been detected using small angle X-ray scattering measurements. The LLC/C 60 hybrids with c TTAO = 80 wt% were then subjected to tribological measurements, and an obvious reduction in their friction coefficients and wear volumes was observed. The C 60 /TTAO weight ratio at which the best tribological performance appears was determined to be 0.01. Our results indicate that the combination of C 60 and catanionic LLCs could lead to the appearance of a new generation of environmentally-benign lubricants.

  10. The happy marriage between electron-phonon superconductivity and Mott physics in Cs3C60: A first-principle phase diagram

    Science.gov (United States)

    Capone, Massimo; Nomura, Yusuke; Sakai, Shiro; Giovannetti, Gianluca; Arita, Ryotaro

    The phase diagram of doped fullerides like Cs3C60 as a function of the spacing between fullerene molecules is characterized by a first-order transition between a Mott insulator and an s-wave superconductor with a dome-shaped behavior of the critical temperature. By means of an ab-initio modeling of the bandstructure, the electron-phonon interaction and the interaction parameter and a Dynamical Mean-Field Theory solution, we reproduce the phase diagram and demonstrate that phonon superconductivity benefits from strong correlations confirming earlier model predictions. The role of correlations is manifest also in infrared measurements carried out by L. Baldassarre. The superconducting phase shares many similarities with ''exotic'' superconductors with electronic pairing, suggesting that the anomalies in the ''normal'' state, rather than the pairing glue, can be the real common element unifying a wide family of strongly correlated superconductors including cuprates and iron superconductors

  11. Competitive photometric enzyme immunoassay for fullerene C60 and its derivatives using a fullerene conjugated to horseradish peroxidase

    International Nuclear Information System (INIS)

    Hendrickson, Olga D.; Smirnova, Natalya I.; Zherdev, Anatoly V.; Dzantiev, Boris B.; Sveshnikov, Peter G.

    2016-01-01

    The article describes a highly sensitive single-step microplate enzyme immunoassay of the ELISA type for fullerene C 60 and its derivatives. Monoclonal anti-fullerene antibodies and a conjugate between fullerene and horseradish peroxidase were used as specific reagents. A direct competitive ELISA was carried out that was based on antibodies immobilized in the well of a microtiter plate, a peroxidase-labeled antigen, and detection via the dye formed from 3,3′,5,5′-tetramethylbenzidine and hydrogen peroxide. Both pristine fullerene C 60 and its water-soluble forms can be determined. The detection limits are 1.5 ng∙mL −1 for fullerene C 60 , and between 0.1 and 1.3 ng∙mL −1 for its derivatives. This ELISA format allows for almost two-fold reduction of the time needed for the assay in comparison to indirect scheme with labeled antibodies. (author)

  12. Effect of plasma oscillations of C60 collectivized electrons on photoionization of endohedral noble-gas atoms

    International Nuclear Information System (INIS)

    Amusia, M. Ya.; Baltenkov, A. S.

    2006-01-01

    It is demonstrated that outer and inner electron shells, including that formed by collectivized electrons of the fullerene C 60 , affects dramatically the cross section of the subvalent ns subshells of the noble-gas endohedral atoms A-C 60 . The calculations are performed within the framework of a very simple, so-called ''orange skin,'' model that makes it possible, in spite of its simplicity, to take into account the modification of the ns subshell due to its interaction with inner and outer atomic shells, as well as with the collectivized electrons of the C 60 . As a concrete example, we consider the Xe 5s electrons completely collectivized by the powerful action of the Xe close and remote multielectron neighboring shells

  13. Modulation of cisplatin-induced reactive oxygen species production by fullerene C(60 in normal and transformed lymphoid cells

    Directory of Open Access Journals (Sweden)

    D. V. Franskevych

    2016-02-01

    Full Text Available The early response of normal (Wistar rat thymocytes and transformed (mice lymphoid leukemia L1210 cells to treatment with anticancer drug cisplatin or to combined treatment with cisplatin and carbon nanostructure fullerene C60 was studied. We demonstrated with fluorescent probes DCFH-DA and TMRE that cisplatin at concentration 1 μg/ml induced reactive oxygen species (ROS production and decreased the value of mitochondrial membrane potential in both cell types. The combined treatment with cisplatin (1 μg/ml and fullerene C60 (7.2 μg/ml was shown to be followed by oppositely directed modulation of ROS production in thymocytes and L1210 cells. Cisplatin-induced ROS production was intensified in L1210 cells, while in thymocytes it was decreased. It is supposed that the different effects of combined treatment are associated with peculiarities of fullerene C60 accumulation and localization in normal and cancer cells.

  14. Angular distributions of projectiles following electron capture from C60 by 2.5-keV Ar8+

    International Nuclear Information System (INIS)

    Walch, B.; Thumm, U.; Stoeckli, M.; Cocke, C.L.; Klawikowski, S.

    1998-01-01

    Experimental measurements of the projectile angular distributions for 2.5-keV Ar 8+ ions capturing one to five electrons from a gas-phase C 60 target are presented. The number of captured electrons was determined by demanding a coincidence between the scattered projectile and a charge-state-analyzed intact C 60 recoil ion. The results are compared to calculations based on a dynamical classical overbarrier model. Good agreement is obtained only if the influence on the projectile trajectory by the large polarizability of the C 60 target is taken into account, thereby making the collective dielectric response of the cluster target observable in a scattering experiment. copyright 1998 The American Physical Society

  15. Tandem organic light-emitting diodes with buffer-modified C60/pentacene as charge generation layer

    Science.gov (United States)

    Wang, Zhen; Zheng, Xin; Liu, Fei; Wang, Pei; Gan, Lin; Wang, Jing-jing

    2017-09-01

    Buffer-modified C60/pentacene as charge generation layer (CGL) is investigated to achieve effective performance of charge generation. Undoped green electroluminescent tandem organic light-emitting diodes (OLEDs) with multiple identical emissive units and using buffer-modified C60/pentacene organic semiconductor heterojunction (OHJ) as CGL are demonstrated to exhibit better current density and brightness, compared with conventional single-unit devices. The current density and brightness both can be significantly improved with increasing the thickness of Al. However, excessive thickness of Al seriously decreases the transmittance of films and damages the interface. As a result, the maximum current efficiency of 1.43 cd·A-1 at 30 mA·cm-2 can be achieved for tandem OLEDs with optimal thickness of Al. These results clearly demonstrate that Cs2CO3/Al is an effective buffer for C60/pentacene-based tandem OLEDs.

  16. Inhibition of thrombin by functionalized C60 nanoparticles revealed via in vitro assays and in silico studies.

    Science.gov (United States)

    Liu, Yanyan; Fu, Jianjie; Pan, Wenxiao; Xue, Qiao; Liu, Xian; Zhang, Aiqian

    2018-01-01

    The studies on the human toxicity of nanoparticles (NPs) are far behind the rapid development of engineered functionalized NPs. Fullerene has been widely used as drug carrier skeleton due to its reported low risk. However, different from other kinds of NPs, fullerene-based NPs (C 60 NPs) have been found to have an anticoagulation effect, although the potential target is still unknown. In the study, both experimental and computational methods were adopted to gain mechanistic insight into the modulation of thrombin activity by nine kinds of C 60 NPs with diverse surface chemistry properties. In vitro enzyme activity assays showed that all tested surface-modified C 60 NPs exhibited thrombin inhibition ability. Kinetic studies coupled with competitive testing using 3 known inhibitors indicated that six of the C 60 NPs, of greater hydrophobicity and hydrogen bond (HB) donor acidity or acceptor basicity, acted as competitive inhibitors of thrombin by directly interacting with the active site of thrombin. A simple quantitative nanostructure-activity relationship model relating the surface substituent properties to the inhibition potential was then established for the six competitive inhibitors. Molecular docking analysis revealed that the intermolecular HB interactions were important for the specific binding of C 60 NPs to the active site canyon, while the additional stability provided by the surface groups through van der Waals interaction also play a key role in the thrombin binding affinity of the NPs. Our results suggest that thrombin is a possible target of the surface-functionalized C 60 NPs relevant to their anticoagulation effect. Copyright © 2017. Published by Elsevier B.V.

  17. Schroedinger--Dirac spaces of entire functions

    International Nuclear Information System (INIS)

    De Branges, L.

    1977-01-01

    A study is made of some Hilbert spaces of entire function which appear in the quantum mechanical theory of the hydrogen atoms. These spaces are examples in the theory of Hilbert spaces whose elements are entire functions and which have certain given properties. 1 reference

  18. Accurate quantum calculations of translation-rotation eigenstates in electric-dipole-coupled H2O@C60 assemblies

    Science.gov (United States)

    Felker, Peter M.; Bačić, Zlatko

    2017-09-01

    We present methodology for variational calculation of the 6 n -dimensional translation-rotation (TR) eigenstates of assemblies of n H2O@C60 moieties coupled by dipole-dipole interactions. We show that the TR Hamiltonian matrix for any n can be constructed from dipole-dipole matrix elements computed for n = 2 . We present results for linear H2O@C60 assemblies. Two classes of eigenstates are revealed. One class comprises excitations of the 111 rotational level of H2O. The lowest-energy 111 -derived eigenstate for each assembly exhibits significant dipole ordering and shifts down in energy with the assembly size.

  19. Low band gap and ionic bonding with charge transfer, threshold in the polymeric lithium fulleride Li(4)C(60)

    NARCIS (Netherlands)

    Macovez, Roberto; Savage, Rebecca; Schiessling, Joachim; Kamaras, Katalin; Rudolf, Petra; Venema, L.C.

    2008-01-01

    We demonstrate the growth of crystalline Li(4)C(60) films. The low-energy electron diffraction pattern of the films indicates the formation of polymer chains in the plane of the surface, consistent with the reported crystal structure. Electron energy loss and photoemission spectra identify the

  20. Infrared photoexcitation spectroscopy of conducting polymer and C60 composites: direct evidence of photo-induced electron transfer

    NARCIS (Netherlands)

    Lee, Kwanghee; Janssen, R.A.J.; Sariciftci, N.S.; Heeger, A.J.

    1994-01-01

    We report direct spectral evidence of photoinduced electron transfer from the excited state of conducting polymer onto C60 by infrared photoexcitation spectroscopy, from 0.01 eV (100 cm-1) to 1.3 eV (11,000 cm-1). The photoinduced absorption spectra of poly(3-octylthiophene) (P30T) and

  1. AC/DC electrical conduction and dielectric properties of PMMA/PVAc/C60 down-shifting nanocomposite films

    Science.gov (United States)

    El-Bashir, S. M.; Alwadai, N. M.; AlZayed, N.

    2018-02-01

    Polymer nanocomposite films were prepared by doping fullerene C60 in polymer blend composed of polymethacrylate/polyvinyl acetate blends (PMMA/PVAc) using solution cast technique. The films were characterized by differential scanning calorimeter (DSC), Transmission electron microscope (TEM), DC/AC electrical conductivity and dielectric measurements in the frequency range (100 Hz- 1 MHz). The glass transition temperature, Tg, was increased by increasing the concentration of fullerene C60; this property reflects the increase of thermal stability by increasing the nanofiller content. The DC and AC electrical conductivities were enhanced by increasing C60 concentration due to the electron hopping or tunneling between filled and empty localized states above Tg. The relaxation time was determined from the αβ -relaxations and found to be attenuated by increasing the temperature as a typical behavior of amorphous polymers. The calculated values of thermodynamic parameters revealed the increase of molecular stability by increasing the doping concentration; this feature supports the application of PMMA/PVAc/C60 nanocomposite films in a wide scale of solar energy conversion applications such as luminescent down-shifting (LDS) coatings for photovoltaic cells.

  2. A first-principle investigation into effect of B-and BN-doped C60 in ...

    Indian Academy of Sciences (India)

    Annual Meetings · Mid Year Meetings · Discussion Meetings · Public Lectures · Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Bulletin of Materials Science; Volume 40; Issue 7. A first-principle investigation into effect of B- and BN-doped C 60 in lowering dehydrogenation of MXH 4 ...

  3. Magnetically modulated microwave absorption (MMMA) measurements at low magnetic fields on the ferromagnetic state of [TDAE]C60

    International Nuclear Information System (INIS)

    Bele, P.; Brunner, H.

    1997-01-01

    The ferromagnetic state and reported superconductivity of [TDAE]C 60 (where TDAE is tetrakis(dimethylamino)ethylene) are investigated by magnetically modulated microwave absorption (MMMA). The results are compared with those reported using alternative physical measurement techniques, and a hypothesis proposed to explain the observed behavior. No evidence for superconductivity is found. (orig.)

  4. Pronounced low-frequency vibrational thermal transport in C60 fullerite realized through pressure-dependent molecular dynamics simulations

    Science.gov (United States)

    Giri, Ashutosh; Hopkins, Patrick E.

    2017-12-01

    Fullerene condensed-matter solids can possess thermal conductivities below their minimum glassy limit while theorized to be stiffer than diamond when crystallized under pressure. These seemingly disparate extremes in thermal and mechanical properties raise questions into the pressure dependence on the thermal conductivity of C60 fullerite crystals, and how the spectral contributions to vibrational thermal conductivity changes under applied pressure. To answer these questions, we investigate the effect of strain on the thermal conductivity of C60 fullerite crystals via pressure-dependent molecular dynamics simulations under the Green-Kubo formalism. We show that the thermal conductivity increases rapidly with compressive strain, which demonstrates a power-law relationship similar to their stress-strain relationship for the C60 crystals. Calculations of the density of states for the crystals under compressive strains reveal that the librational modes characteristic in the unstrained case are diminished due to densification of the molecular crystal. Over a large compression range (0-20 GPa), the Leibfried-Schlömann equation is shown to adequately describe the pressure dependence of thermal conductivity, suggesting that low-frequency intermolecular vibrations dictate heat flow in the C60 crystals. A spectral decomposition of the thermal conductivity supports this hypothesis.

  5. A first-principle investigation into effect of B-and BN-doped C60 in ...

    Indian Academy of Sciences (India)

    principle investigation into effect of B- and BN-doped C 60 in lowering dehydrogenation of MXH 4 (where M = Na, Li and X = Al, B). MEENAKSHI DEEPAK AGNIHOTRI KIRAN JEET HITESH SHARMA. Volume 40 Issue 7 December 2017 pp 1397-1403 ...

  6. On the possibility of the electron polarization to be the driving force for the C60-TMB nanowire growth

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Geng, Junfeng; Solov'yov, Andrey V.

    2009-01-01

    The effect of electron polarization has been suggested to explain the exceptionally large length-to width aspect ratio (more than 3000) in recently observed C_60-based nanowires. The theoretical estimates performed in the present Letter show that at room temperature the effect of electron polariz...

  7. Photo-assisted electrochemical abatement of trifluralin using a cathode containing a C60-carbon nanotubes composite.

    Science.gov (United States)

    Hasanzadeh, Aliyeh; Khataee, Alireza; Zarei, Mahmoud; Joo, Sang Woo

    2018-05-01

    This work reports the potential application of modified gas-diffusion electrode (GDE) with C 60 -CNT composite, as a stable and efficient cathode material for degradation of trifluralin (TRL) pesticide by photo-assisted electrochemical (PE) process. C 60 -CNT composite was prepared and characterized. Subsequently, a novel C 60 -CNT composite modified GDE cathode was developed and the electrochemical and physical characteristics of the modified GDEs were studied. C 60 -CNT composite/GDE showed great efficiencies for electro-generating H 2 O 2 , owing to huge surface area and high conductivity. Afterwards, a comparative study of TRL oxidation via photolysis, anodic oxidation (AO) and PE processes using C 60 -CNT composite/GDE revealed the degradation percentages of 42.2, 48.5 and 93.4%, respectively, after 180 min of treatment. The TRL degradation followed a pseudo-first-order kinetics, being faster in the order: photolysis composite/GDE exhibited great performance for the degradation of TRL (20 mg L -1 ) under its original pH, Na 2 SO 4 electrolyte concentration of 0.05 mol L -1 , applied current intensity of 300 mA, and flow rate of 12.5 L h -1 . TOC results displayed that 92.8% of TRL was mineralized after 8 h of PE process. In addition, a plausible pathway for mineralization of TRL was proposed according to the identified by-products detected by means of gas chromatography-mass spectroscopy (GC-MS), High-performance liquid chromatography (HPLC) and ion chromatography analyses. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Relative ion yields in mammalian cell components using C60 SIMS

    Science.gov (United States)

    Keskin, Selda; Piwowar, Alan; Hue, Jonathan; Shen, Kan; Winograd, Nicholas

    2013-01-01

    Time of flight secondary ion mass spectrometry has been used to better understand the influence of molecular environment on the relative ion yields of membrane lipid molecules found in high abundance in a model mammalian cell line, RAW264.7. Control lipid mixtures were prepared to simulate lipid–lipid interactions in the inner and outer leaflet of cell membranes. Compared with its pure film, the molecular ion yields of 1,2-dioleoyl-sn-glycero-3-phosphocholine and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine are suppressed when mixed with 2-dipalmitoyl-sn-glycero-3-phosphocholine. In the mixture, proton competition between 1,2-dioleoyl-sn-glycero-3-phosphocholine, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, and 2-dipalmitoyl-sn-glycero-3-phosphocholine led to lower ionization efficiency. The possible mechanism for ion suppression was also investigated with 1H and 13C nuclear magnetic resonance spectroscopy. The formation of a hydroxyl bond in lipid mixtures confirms the mechanism involving proton exchange with the surrounding environment. Similar effects were observed for lipid mixtures mimicking the composition of the inner leaflet of cell membranes. The secondary molecular ion yield of 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine was observed to be enhanced in the presence of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine. PMID:25140069

  9. Effect of intra-membrane C60 fullerenes on the modulus of elasticity and the mechanical resistance of gel and fluid lipid bilayers

    Science.gov (United States)

    Zhou, Jihan; Liang, Dehai; Contera, Sonia

    2015-10-01

    Penetration and partition of C60 to the lipid bilayer core are both relevant to C60 toxicity, and useful to realise C60 biomedical potential. A key aspect is the effect of C60 on bilayer mechanical properties. Here, we present an experimental study on the mechanical effect of the incorporation of C60 into the hydrophobic core of fluid and gel phase zwitterionic phosphatidylcholine (PC) lipid bilayers. We demonstrate its incorporation inside the hydrophobic lipid core and the effect on the packing of the lipids and the vesicle size using a combination of infrared (IR) spectroscopy, atomic force microscopy (AFM) and laser light scattering. Using AFM we measured the Young's modulus of elasticity (E) of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) in the absence (presence) of intra-membranous C60 at 24.5 °C. E of fluid phase supported bilayers is not altered by C60, but E increases with incorporation of C60 in gel phase bilayers. The increase is higher for longer hydrocarbon chains: 1.6 times for DPPC and 2 times for DSPC. However the mechanical resistance of gel phase bilayers of curved bilayered structures decreases with the incorporation of C60. Our combined results indicate that C60 causes a decrease in gel phase lipid mobility, i.e. an increase in membrane viscosity.

  10. Flat-on ambipolar triphenylamine/C60 nano-stacks formed from the self-organization of a pyramid-sphere-shaped amphiphile.

    Science.gov (United States)

    Liang, Wei-Wei; Huang, Chi-Feng; Wu, Kuan-Yi; Wu, San-Lien; Chang, Shu-Ting; Cheng, Yen-Ju; Wang, Chien-Lung

    2016-04-21

    A giant amphiphile, which is constructed with an amorphous nano-pyramid (triphenylamine, TPA) and a crystalline nano-sphere (C 60 ), was synthesized. Structural characterization indicates that this pyramid-sphere-shaped amphiphile ( TPA-C 60 ) forms a solvent-induced ordered phase, in which the two constituent units self-assemble into alternating stacks of two-dimensional (2D) TPA and C 60 nano-sheets. Due to the complexity of the molecular structure and the amorphous nature of the nano-pyramid, phase formation was driven by intermolecular C 60 -C 60 interactions and the ordered phase could not be reformed from the TPA-C 60 melt. Oriented crystal arrays of TPA-C 60 , which contain flat-on TPA/C 60 nano-stacks, can be obtained via a PDMS-assisted crystallization (PAC) technique. The flat-on dual-channel supramolecular structure of TPA-C 60 delivered ambipolar and balanced charge-transport characteristics with an average μ e of 2.11 × 10 -4 cm 2 V -1 s -1 and μ h of 3.37 × 10 -4 cm 2 V -1 s -1 . The anisotropic charge-transport ability of the pyramid-sphere-shaped amphiphile was further understood based on the lattice structure and the lattice orientation of TPA-C 60 revealed from electron diffraction analyses.

  11. UOP HRM 531 Entire Course NEW

    OpenAIRE

    ADMIN

    2018-01-01

    UOP HRM 531 Entire Course NEW Check this A+ tutorial guideline at http://www.hrm531assignment.com/hrm-531-uop/hrm-531-entire-course -latest For more classes visit http://www.hrm531assignment.com HRM 531 Week 1 Employment Law Report (2 Papers) HRM 531 Week 2 Change Management Impact (2 Papers) HRM 531 Week 3 Individual Compensation and Benefits Strategy (2 Papers) HRM 531 Week 3 Team Salary Inequities Case Study AstraZeneca (2 Papers) HRM 531 W...

  12. Entire cyclic cohomology and modular theory

    International Nuclear Information System (INIS)

    Stoytchev, O.Ts.

    1992-04-01

    We display a close relationship between C* and W*-dynamical systems with KMS states on them and entire cyclic cohomology theory. We construct a character form which assigns to each such system (A, α, R) an even entire cyclic cocycle of the subalgebra A of differentiable (with respect to the given automorphism group) elements of A. We argue that the most interesting case is the von Neumann algebra one, where the automorphism group is determined uniquely by the faithful normal state on the algebra (the modular group) and where the character may provide important information about the algebra. (author). 11 refs

  13. The class of n-entire operators

    International Nuclear Information System (INIS)

    Silva, Luis O; Toloza, Julio H

    2013-01-01

    We introduce a classification of simple, regular, closed symmetric operators with deficiency indices (1, 1) according to a geometric criterion that extends the classical notions of entire operators and entire operators in the generalized sense due to M G Krein. We show that these classes of operators have several distinctive properties, some of them related to the spectra of their canonical self-adjoint extensions. In particular, we provide necessary and sufficient conditions on the spectra of two canonical self-adjoint extensions of an operator for it to belong to one of our classes. Our discussion is based on some recent results in the theory of de Branges spaces. (paper)

  14. Enhanced performance of C60 organic field effect transistors using a tris(8-hydroxyquinoline) aluminum buffer layer

    Energy Technology Data Exchange (ETDEWEB)

    Zheng Hong; Cheng Xiaoman; Tian Haijun [Institute of Material Physics, Key Laboratory of Display Material and Photoelectric Devices, Ministry of Education, Tianjin University of Technology, Tianjin 300384 (China); Zhao Geng, E-mail: zheng_033@163.com [School of Science, Tianjin University of Technology, Tianjin 300384 (China)

    2011-09-15

    We have investigated the properties of C60-based organic field effect transistors (OFETs) with a tris(8-hydroxyquinoline) aluminum (Alq3) buffer layer inserted between the source/drain electrodes and the active material. The electrical characteristics of OFETs are improved with the insertion of Alq3 film. The peak field effect mobility is increased to 1.28 x 10{sup -2} cm{sup 2}/(V{center_dot}s) and the threshold voltage is decreased to 10 V when the thickness of the Alq3 is 10 nm. The reason for the improved performance of the devices is probably due to the prevention of metal atoms diffusing into the C60 active layer and the reduction of the channel resistance in Alq3 films. (semiconductor devices)

  15. Growth of Fullerene Fragments Using the Diels-Alder Cycloaddition Reaction: First Step towards a C60 Synthesis by Dimerization

    Directory of Open Access Journals (Sweden)

    Julio A. Alonso

    2013-02-01

    Full Text Available Density Functional Theory has been used to model the Diels-Alder reactions of the fullerene fragments triindenetriphenilene and pentacyclopentacorannulene with ethylene and 1,3-butadiene. The purpose is to prove the feasibility of using Diels-Alder cycloaddition reactions to grow fullerene fragments step by step, and to dimerize fullerene fragments, as a way to obtain C60. The dienophile character of the fullerene fragments is dominant, and the reaction of butadiene with pentacyclopentacorannulene is favored.

  16. Tunability of RF-Responses by Plasmonic Dielectric Amplification Using Branched e- -Polarizable C60-Adducts on Magnetic (Postprint)

    Science.gov (United States)

    2016-07-18

    photogenerated SPR energy in the intermediate gold layer, sandwiched between the C60 (>DPAF-C9)x-derived fullerosome membrane and the highly magnetic γ...nanolayer. We hypothesized that the prolong accumulation (or trapping) of photogenerated SPR energy in the intermediate gold layer, sandwiched...hypothesized that the long-period accumulation (or trapping)3−5 of photogenerated SPR energy in the intermediate gold layer sandwiched between the

  17. First-principles investigation of quantum transport through an endohedral N@C60 in the Coulomb blockade regime.

    Science.gov (United States)

    Yu, Zhizhou; Chen, Jian; Zhang, Lei; Wang, Jian

    2013-12-11

    We report an investigation of Coulomb blockade transport through an endohedral N@C60 weakly coupled with aluminum leads, employing the first-principles method combined with the Keldysh non-equilibrium Green's function derived from the equation of motion beyond the Hartree-Fock approximation. The differential conductance characteristics of the molecular device are calculated within the Coulomb blockade regime, which shows the Coulomb diamond as observed experimentally. When the gate voltage is less than that of the degeneracy point, there are two peaks in the differential conductance with an excited state induced by the change of the exchange interaction between the spin of C60 and the encapsulated nitrogen atom due to the transition from N@C(1-)(60) to N@C(2-)(60), while for a gate voltage larger than that of the degeneracy point, no excited state is available due to the quenching of exchange energy. As a result, there is only one Coulomb blockade peak in the differential conductance from the electron tunneling through the highest energy level below the Fermi level. Our first-principles results are in good agreement with experimental data obtained by an endohedral N@C60 molecular device.

  18. Electronic Structure of C60/Zinc Phthalocyanine/V₂O₅ Interfaces Studied Using Photoemission Spectroscopy for Organic Photovoltaic Applications.

    Science.gov (United States)

    Lim, Chang Jin; Park, Min Gyu; Kim, Min Su; Han, Jeong Hwa; Cho, Soohaeng; Cho, Mann-Ho; Yi, Yeonjin; Lee, Hyunbok; Cho, Sang Wan

    2018-02-18

    The interfacial electronic structures of a bilayer of fullerene (C 60 ) and zinc phthalocyanine (ZnPc) grown on vanadium pentoxide (V₂O₅) thin films deposited using radio frequency sputtering under various conditions were studied using X-ray and ultraviolet photoelectron spectroscopy. The energy difference between the highest occupied molecular orbital (HOMO) level of the ZnPc layer and the lowest unoccupied molecular orbital (LUMO) level of the C 60 layer was determined and compared with that grown on an indium tin oxide (ITO) substrate. The energy difference of a heterojunction on all V₂O₅ was found to be 1.3~1.4 eV, while that on ITO was 1.1 eV. This difference could be due to the higher binding energy of the HOMO of ZnPc on V₂O₅ than that on ITO regardless of work functions of the substrates. We also determined the complete energy level diagrams of C 60 /ZnPc on V₂O₅ and ITO.

  19. The influence of oxygen adsorption on the NEXAFS and core-level XPS spectra of the C60 derivative PCBM

    International Nuclear Information System (INIS)

    Brumboiu, Iulia Emilia; Eriksson, Olle; Brena, Barbara; Ericsson, Leif; Hansson, Rickard; Moons, Ellen

    2015-01-01

    Fullerenes have been a main focus of scientific research since their discovery due to the interesting possible applications in various fields like organic photovoltaics (OPVs). In particular, the derivative [6,6]-phenyl-C 60 -butyric acid methyl ester (PCBM) is currently one of the most popular choices due to its higher solubility in organic solvents compared to unsubstituted C 60 . One of the central issues in the field of OPVs is device stability, since modules undergo deterioration (losses in efficiency, open circuit voltage, and short circuit current) during operation. In the case of fullerenes, several possibilities have been proposed, including dimerization, oxidation, and impurity related deterioration. We have studied by means of density functional theory the possibility of oxygen adsorption on the C 60 molecular moiety of PCBM. The aim is to provide guidelines for near edge X-ray absorption fine structure (NEXAFS) and X-ray photoelectron spectroscopy (XPS) measurements which can probe the presence of atomic or molecular oxygen on the fullerene cage. By analysing several configurations of PCBM with one or more adsorbed oxygen atoms, we show that a joint core level XPS and O1s NEXAFS investigation could be effectively used not only to confirm oxygen adsorption but also to pinpoint the bonding configuration and the nature of the adsorbate

  20. Properties of K,Rb-intercalated C60 encapsulated inside carbon nanotubes called peapods derived from nuclear magnetic resonance

    KAUST Repository

    Mahfouz, Remi

    2015-09-18

    We present a detailed experimental study on how magnetic and electronic properties of Rb,K-intercalated C60 encapsulated inside carbon nanotubes called peapods can be derived from 13C nuclear magnetic resonance investigations. Ring currents do play a basic role in those systems; in particular, the inner cavities of nanotubes offer an ideal environment to investigate the magnetism at the nanoscale. We report the largest diamagnetic shifts down to −68.3 ppm ever observed in carbon allotropes, which is connected to the enhancement of the aromaticity of the nanotube envelope upon intercalation. The metallization of intercalated peapods is evidenced from the chemical shift anisotropy and spin-lattice relaxation (T1) measurements. The observed relaxation curves signal a three-component model with two slow and one fast relaxing components. We assigned the fast component to the unpaired electrons charged C60 that show a phase transition near 100 K. The two slow components can be rationalized by the two types of charged C60 at two different positions with a linear regime following Korringa behavior, which is typical for metallic system and allow us to estimate the density of sate at Fermi level n(EF).

  1. Fate and biological effects of silver, titanium dioxide, and C60 (fullerene) nanomaterials during simulated wastewater treatment processes

    International Nuclear Information System (INIS)

    Wang, Yifei; Westerhoff, Paul; Hristovski, Kiril D.

    2012-01-01

    As engineered nanomaterials (NMs) become used in industry and commerce their loading to sewage will increase. In this research, sequencing batch reactors (SBRs) were operated with hydraulic (HRT) and sludge (SRT) retention times representative of full-scale biological WWTPs for several weeks. Under environmentally relevant NM loadings and biomass concentrations, NMs had negligible effects on ability of the wastewater bacteria to biodegrade organic material, as measured by chemical oxygen demand (COD). Carboxy-terminated polymer coated silver nanoparticles (fn-Ag) were removed less effectively (88% removal) than hydroxylated fullerenes (fullerols; >90% removal), nano TiO 2 (>95% removal) or aqueous fullerenes (nC 60 ; >95% removal). Experiments conducted over 4 months with daily loadings of nC 60 showed that nC 60 removal from solution depends on the biomass concentration. Under conditions representative of most suspended growth biological WWTPs (e.g., activated sludge), most of the NMs will accumulate in biosolids rather than in liquid effluent discharged to surface waters. Significant fractions of fn-Ag were associated with colloidal material which suggests that efficient particle separation processes (sedimentation or filtration) could further improve removal of NM from effluent.

  2. The Teichmuller Space of an Entire Function

    DEFF Research Database (Denmark)

    Fagella, Nuria; Henriksen, Christian

    2008-01-01

    points of any quasiconformal automorphism that commutes with f and which is homotopic to the identity, rel. the ideal boundary of the domain. As a consequence, the general framework of McMullen and Sullivan [McMS98] for rational functions applies also to entire functions and we can apply it to study...

  3. AFM image of an entire polygene chromosome

    International Nuclear Information System (INIS)

    Li Minqian; Takeuchi; Ikai, A.

    1994-01-01

    The author present AFM images of an entire polygene chromosome of Drosophila for the first time. Comparing with conventional optical microscope, the AFM image of the polygene chromosomes provides much higher resolution and 3-D measurement capability which will lead to finer scale gene mapping and identification

  4. The structures of endohedral complexes between C60 and alkali or halogen atoms, and the interactions between them - a theoretical approach

    International Nuclear Information System (INIS)

    Yan Jimin; Xu Zhijin

    1994-01-01

    In this paper, some properties of endohedral complexes formed between C 60 and alkali or halogen atoms, (Alk rateat C 60 ) (Alk = Li, Na, K, Rb, Cs) and (Hal rateat C 60 ) (Hal = F, Cl, Br, I), which include electronic structures, stabilities, potential energies at different positions of the endohedral atoms, cage radius changes and charge distributions, have been computed by the quantum-chemical EHMO/ASED method. The computational results show that the potential energies of the systems have minima when the endohedral atoms are put at the center of the C 60 cage for K, Rb, Cs and F, Cl, Br, I, but the minimum points of the potential energies are at r ∝ 1.6 A for Li and at r ∝ 1.3 A for Na deviated from the cage center. The curves of potential energies along five different directions vary only a little, that is, the potential field is basically sphero-symmetrical in the C 60 cage. It has been pointed out that the endohedral complex systems of C 60 with alkalis and halogens, (Alk rateat aC 60 ) and (Hal rateat C 60 ), can be separated into two subsystems quite well, in which the interaction between the endohedral atom and the C's of the C 60 cage can be described with the (exp-6-1) potential function. (orig.)

  5. Fourier photospectroscopy of Xe-C60 through a Xe 4d resonance window: theory versus recent experiment

    International Nuclear Information System (INIS)

    Patel, Aakash B; Chakraborty, Himadri S

    2011-01-01

    The photoionization cross section of endohedral Xe-C 60 over a Xe 4d giant resonance energy region, calculated in the time-dependent local density approximation, is compared with recent measurements (Kilcoyne et al 2010 Phys. Rev. Lett. 105 213001). An analysis based on the Fourier transforms of oscillatory cross sections is performed to derive a number of inherent similarities between the prediction and the data, including a large beating-type oscillation and several others of intermediate size. Results stress the need for more accurate measurements to access the wealth of information about the geometry of the system. (fast track communication)

  6. Photoinduced Optical Spectroscopy of La2CuO4+x Single Crystals and C60 Thin Films

    International Nuclear Information System (INIS)

    Bazhenov, A.V.; Gorbunov, A.V.; Timofeev, V.B.

    1995-01-01

    The evolution of both vibration and electronic spectra of insulating La 2 CuO 4+x single crystals upon charge-transfer gap photoexcitation has been studied by means of photoinduced reflection spectroscopy. Interaction of self-localized hole with some of the A g , B 2g (B 3g ), B 3u optical phonons has been observed. Formation of self-localized hole state and its multiparticle complexes is supposed. Photoinduced absorption in C 60 thin films has been found to differ essentially from that in cuprates

  7. C60 fullereno modificado por haces de iones de baja energía para prevenir el efecto multipactor

    Directory of Open Access Journals (Sweden)

    Galán, L.

    2005-04-01

    Full Text Available C60 fullerene modified by low-energy ion beams of H2 +, N2 +, O2 + y Ar+ has been studied. After ion bombardment, the photoemission spectra obtained using synchrotron radiation show an increase of the density of states just bellow the Fermi level. Ion bombarment of C60 with 50 eV energy and 4×1014 ion/cm2 fluence is sufficient to modify the cage structure of the fullerene and to obtain graphitic amorphous carbon. Upon bombarding with an energy of 50 eV, implantation of the nitrogen and the oxygen ions was observed, while implantation of the hydrogen and argon ions was small. The maximum secondary emission yield of C60 thin films is lower than 1.3 even after air exposure. A significant improvement on the secondary emission properties can be obtained after bombardment by low-energy Ar+ and N2 + ion beams.Se ha estudiado la interacción de los iones H2 +, N2 +, O2 + y Ar+ de baja energía con películas delgadas de fullereno C60. Después del bombardeo iónico, la densidad de estados cerca del nivel de Fermi aumenta de forma apreciable, según se observa en los espectros de fotoemisión obtenidos usando radiación sincrotrón. El bombardeo iónico con una energía de tan sólo 50 eV y una fluencia de 4x1014 ion/cm2 es suficiente para modificar la simétrica estructura de caja del fullereno y obtener carbono amorfo grafítico. El nitrógeno y el oxígeno se implantan al bombardear con una energía de 50 eV, mientras que la implantación es despreciable en el caso del hidrógeno y argon. Las películas de fullereno poseen un coeficiente máximo de emisión secundaria inferior a 1.3 incluso después de su exposición al aire, el cual disminuye después del bombardeo con iones de N2 + y Ar+.

  8. Calculations of the thermal expansion, cohesive energy and thermodynamic stability of a Van der Waals crystal - fullerene C60

    International Nuclear Information System (INIS)

    Zubov, V.I.; Tretiakov, N.P.; Teixeira Rabelo, J.N.; Sanchez Ortiz, J.F.

    1994-01-01

    The temperature dependence of the intermolecular distance and the cohesive energy in the high-temperature modification of C 60 solid fullerene was studied on basis of the correlative method of unsymmetrized self-consistent field. The central intermolecular potential of Girifalco and its approximation by Yakub were used. We conclude about the decisive role of anharmonic effects at high temperatures. The discrepancy between the calculated and experimental values of intermolecular distance does not exceed 0.8% on the whole temperature interval. The temperature of loss of thermodynamic stability was obtained (∼1915 K) and a possible melting temperature was estimated (∼1400 K). ((orig.))

  9. Asymmetric fission and evaporation of Cr+60 (r = 2-4) fullerene ions in ion-C60 collisions: III. Universal behaviour of fission

    International Nuclear Information System (INIS)

    Bordenave-Montesquieu, D; Bordenave-Montesquieu, A; Rentenier, A; Moretto-Capelle, P

    2005-01-01

    The behaviour of the asymmetrical fission (AF) scheme (correlated ion distributions) against the collision conditions is investigated using H + x (x = 1-3) and He + projectiles in the 1-130 keV collision energy range. The present work is an extension of our recent publications on this topic using 11 keV protons (Rentenier et al 2004 J. Phys. B: At. Mol. Opt. Phys. 37 2429 and 2455). The threshold for AF is observed at 2 keV proton energy corresponding to a maximum deposited energy equal to about 41 eV. The main result concerns the fragment distributions resulting from AF of C r+ 60 ions, and secondary dissociation of even-n C + n fragments, which are both found to remain independent of the projectile species and collision velocity. These findings indicate that they are insensitive to the internal energy distributions of the parent ions. In addition, a contribution of binary collisions between the projectile and individual carbon atoms of the C 60 molecule to AF is identified in the C + 1 production at the lowest collision velocities, the so-called impulsive fragmentation

  10. Progress in Development of C60 Nanoparticle Plasma Jet for Diagnostic of Runaway Electron Beam-Plasma Interaction and Disruption Mitigation Study for ITER

    Science.gov (United States)

    Bogatu, I. N.; Thompson, J. R.; Galkin, S. A.; Kim, J. S.

    2013-10-01

    We produced a C60 nanoparticle plasma jet (NPPJ) with uniquely fast response-to-delivery time (~ 1 - 2 ms) and unprecedentedly high momentum (~ 0 . 6 g .km/s). The C60 NPPJ was obtained by using a solid state TiH2/C60 pulsed power cartridge producing ~180 mg of C60 molecular gas by sublimation and by electromagnetic acceleration of the C60 plasma in a coaxial gun (~35 cm length, 96 kJ energy) with the output of a high-density (>1023 m-3) hyper-velocity (>4 km/s) plasma jet. The ~ 75 mg C60/C plasma jet has the potential to rapidly and deeply deliver enough mass to significantly increase electron density (to ne ~ 2 . 4 ×1021 m-3, i.e. ~ 60 times larger than typical DIII-D pre-disruption value, ne 0 ~ 4 ×1019 m-3), and to modify the 'critical electric field' and the runaway electrons (REs) collisional drag during different phases of REs dynamics. The C60 NPPJ, as a novel injection technique, allows RE beam-plasma interaction diagnostic by quantitative spectroscopy of C ions visible/UV line intensity. The system is scalable to ~ 1 - 2 g C60/C plasma jet output and technology is adaptable to ITER acceptable materials (BN and Be) for disruption mitigation. Work supported by US DOE DE-FG02-08ER85196 grant.

  11. Flexible Ag-C60 nano-biosensors based on surface plasmon coupled emission for clinical and forensic applications.

    Science.gov (United States)

    Mulpur, Pradyumna; Yadavilli, Sairam; Mulpur, Praharsha; Kondiparthi, Neeharika; Sengupta, Bishwambhar; Rao, Apparao M; Podila, Ramakrishna; Kamisetti, Venkataramaniah

    2015-10-14

    The relatively low sensitivity of fluorescence detection schemes, which are mainly limited by the isotropic nature of fluorophore emission, can be overcome by utilizing surface plasmon coupled emission (SPCE). In this study, we demonstrate directional emission from fluorophores on flexible Ag-C60 SPCE sensor platforms for point-of-care sensing, in healthcare and forensic sensing scenarios, with at least 10 times higher sensitivity than traditional fluorescence sensing schemes. Adopting the highly sensitive Ag-C60 SPCE platform based on glass and novel low-cost flexible substrates, we report the unambiguous detection of acid-fast Mycobacterium tuberculosis (Mtb) bacteria at densities as low as 20 Mtb mm(-2); from non-acid-fast bacteria (e.g., E. coli and S. aureus), and the specific on-site detection of acid-fast sperm cells in human semen samples. In combination with the directional emission and high-sensitivity of SPCE platforms, we also demonstrate the utility of smartphones that can replace expensive and cumbersome detectors to enable rapid hand-held detection of analytes in resource-limited settings; a much needed critical advance to biosensors, for developing countries.

  12. Analytic equation of state for FCC C60 solid based on analytic mean-field potential approach

    International Nuclear Information System (INIS)

    Sun Jiuxun

    2006-01-01

    The analytic mean-field approach (AMFP) was applied to the FCC C60 solid. For the intermolecular forces the Girifalco potential has been utilized. The analytic expressions for the Helmholtz free energy, internal energy and equation of state have been derived. The numerical results of thermodynamic quantities are compared with the molecular dynamic (MD) simulations and the unsymmetrized self-consistent field approach (CUSF) in the literature. It is shown that our AMFP results are in good agreement with the MD data both at low and high temperatures. The results of CUSF are in accordance with the AMFP at low temperature, but at high temperature the difference becomes prominent. Especially the AMFP predicted that the FCC C60 solid is stable upto 2202 K, the spinodal temperature, in good agreement with 2320 K from the MD simulation. However, the CUST just gives 1916 K, a temperature evidently lower than the MD data. The AMFP qualifies as a useful approach that can reasonably consider the anharmonic effects at high temperature

  13. Glucose biosensing using glassy carbon electrode modified with polyhydroxy-C60, glucose oxidase and ionic-liquid.

    Science.gov (United States)

    Yang, Tian; Yang, Xiao-Lu; Zhang, Yu-Shuai; Xiao, BaoLin; Hong, Jun

    2014-01-01

    Direct electrochemistry of glucose oxidase (GOD) was achieved when an ionic liquid/GOD-Polyhydroxy-C60 functional membrane was confined on a glassy carbon electrode (GCE). The cyclic voltammograms (CVs) of the modified GCE showed a pair of redox peaks with a formal potential (E°') of - 329 ± 2 mV. The heterogeneous electron transfer constant (k(s)) was 1.43 s-1. The modified GCE response to glucose was linear in the range from 0.02 to 2.0 mM. The detection limit was 1 μM. The apparent Michaelis-Menten constant (K(m)(app)) was 1.45 mM.

  14. Static and Dynamic Energetic Disorders in the C 60 , PC 61 BM, C 70 , and PC 71 BM Fullerenes

    KAUST Repository

    Tummala, Naga Rajesh

    2015-09-17

    We use a combination of molecular dynamics simulations and density functional theory calculations to investigate the energetic disorder in fullerene systems. We show that the energetic disorder evaluated from an ensemble average contains contributions of both static origin (time-independent, due to loose packing) and dynamic origin (time-dependent, due to electron-vibration interactions). In order to differentiate between these two contributions, we compare the results obtained from an ensemble average approach with those derived from a time average approach. It is found that in both amorphous C60 and C70 bulk systems, the degrees of static and dynamic disorder are comparable, while in the amorphous PC61BM and PC71BM systems, static disorder is about twice as large as dynamic disorder. © 2015 American Chemical Society.

  15. Electronic structure evolution and energy level alignment at C60/4,4'-cyclohexylidenebis[N,N-bis(4-methylphenyl) benzenamine]/MoOx/indium tin oxide interfaces

    Science.gov (United States)

    Liu, Xiaoliang; Yi, Shijuan; Wang, Chenggong; Wang, Congcong; Gao, Yongli

    2014-04-01

    The electronic structure evolution and energy level alignment have been investigated at interfaces comprising fullerene (C60)/4,4'-cyclohexylidenebis[N,N-bis(4-methylphenyl) benzenamine] (TAPC)/ molybdenum oxide (MoOx)/ indium tin oxide with ultraviolet photoemission spectroscopy and inverse photoemission spectroscopy. With deposition of TAPC upon MoOx, a dipole of 1.58 eV was formed at the TAPC/MoOx interface due to electron transfer from TAPC to MoOx. The highest occupied molecular orbital (HOMO) onset of TAPC was pinned closed to the Fermi level, leading to a p-doped region and thus increasing the carrier concentration at the very interface. The downward band bending and the resulting built-in field in TAPC were favorable for the hole transfer toward the TAPC/MoOx interface. The rigid downward shift of energy levels of TAPC indicated no significant interface chemistry at the interface. With subsequent deposition of C60 on TAPC, a dipole of 0.27 eV was observed at the C60/TAPC heterojunction due to the electron transfer from TAPC to C60. This led to a drop of the HOMO of TAPC near the C60/TAPC interface, and hence further enhanced the band bending in TAPC. The band bending behavior was also observed in C60, similarly creating a built-in field in C60 film and improving the electron transfer away from the C60/TAPC interface. It can be deduced from the interface analysis that a promising maximum open circuit voltage of 1.5 eV is achievable in C60/TAPC-based organic photovoltaic cells.

  16. Exciton-Dissociation and Charge-Recombination Processes in Pentacene/C 60 Solar Cells: Theoretical Insight into the Impact of Interface Geometry

    KAUST Repository

    Yi, Yuanping; Coropceanu, Veaceslav; Brédas, Jean-Luc

    2009-01-01

    The exciton-dissociation and charge-recombination processes in organic solar cells based on pentacene/C60 heterojunctions are investigated by means of quantum-mechanical calculations. The electronic couplings and the rates of exciton dissociation

  17. Genotoxicity, cytotoxicity, and reactive oxygen species induced by single-walled carbon nanotubes and C(60) fullerenes in the FE1-Mutatrade markMouse lung epithelial cells

    DEFF Research Database (Denmark)

    Jacobsen, Nicklas Raun; Pojana, Giulio; White, Paul

    2008-01-01

    in the greatest reactive oxygen species generation followed by SWCNT and C(60) in both cellular and cell-free particle suspensions. C(60) and SWCNT did not increase the level of strand breaks, but significantly increased the level of FPG sensitive sites/oxidized purines (22 and 56%, respectively) determined...... by the comet assay. The mutant frequency in the cII gene was unaffected by 576 hr of exposure to either 100 microg/ml C(60) or SWCNT when compared with control incubations, whereas we have previously reported that carbon black and diesel exhaust particles induce mutations using an identical exposure scenario....... These results indicate that SWCNT and C(60) are less genotoxic in vitro than carbon black and diesel exhaust particles....

  18. A high mobility C60 field-effect transistor with an ultrathin pentacene passivation layer and bathophenanthroline/metal bilayer electrodes

    International Nuclear Information System (INIS)

    Zhou Jian-Lin; Yu Jun-Sheng; Yu Xin-Ge; Cai Xin-Yang

    2012-01-01

    C 60 field-effect transistor (OFET) with a mobility as high as 5.17 cm 2 /V·s is fabricated. In our experiment, an ultrathin pentacene passivation layer on poly-(methyl methacrylate) (PMMA) insulator and a bathophenanthroline (Bphen)/Ag bilayer electrode are prepared. The OFET shows a significant enhancement of electron mobility compared with the corresponding device with a single PMMA insultor and an Ag electrode. By analysing the C 60 film with atomic force microscopy and X-ray diffraction techniques, it is shown that the pentacene passivation layer can contribute to C 60 film growth with the large grain size and significantly improve crystallinity. Moreover, the Bphen buffer layer can reduce the electron contact barrier from Ag electrodes to C 60 film efficiently. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  19. A large-scale association study for nanoparticle C60 uncovers mechanisms of nanotoxicity disrupting the native conformations of DNA/RNA.

    Science.gov (United States)

    Xu, Xue; Wang, Xia; Li, Yan; Wang, Yonghua; Yang, Ling

    2012-09-01

    Nano-scale particles have attracted a lot of attention for its potential use in medical studies, in particular for the diagnostic and therapeutic purposes. However, the toxicity and other side effects caused by the undesired interaction between nanoparticles and DNA/RNA are not clear. To address this problem, a model to evaluate the general rules governing how nanoparticles interact with DNA/RNA is demanded. Here by, use of an examination of 2254 native nucleotides with molecular dynamics simulation and thermodynamic analysis, we demonstrate how the DNA/RNA native structures are disrupted by the fullerene (C60) in a physiological condition. The nanoparticle was found to bind with the minor grooves of double-stranded DNA and trigger unwinding and disrupting of the DNA helix, which indicates C60 can potentially inhibit the DNA replication and induce potential side effects. In contrast to that of DNA, C60 only binds to the major grooves of RNA helix, which stabilizes the RNA structure or transforms the configuration from stretch to curl. This finding sheds new light on how C60 inhibits reverse transcription as HIV replicates. In addition, the binding of C60 stabilizes the structures of RNA riboswitch, indicating that C60 might regulate the gene expression. The binding energies of C60 with different genomic fragments varies in the range of -56 to -10 kcal mol(-1), which further verifies the role of nanoparticle in DNA/RNA damage. Our findings reveal a general mode by which C60 causes DNA/RNA damage or other toxic effects at a systematic level, suggesting it should be cautious to handle these nanomaterials in various medical applications.

  20. Effects of magnetic processing on electrochemical and photoelectrochemical properties of electrodes modified with nanoclusters of a phenothiazine-C60 linked compound

    International Nuclear Information System (INIS)

    Yonemura, H; Yamada, S; Wakita, Y; Moribe, S; Fujiwara, Y; Tanimoto, Y

    2009-01-01

    Effects of magnetic processing on morphological, electrochemical, and photoelectrochemical properties of electrodes modified with nanoclusters of a phenothiazine-C 60 linked compound with four methylene group (Ph(4)C 60 ) were examined in the absence and presence of magnetic processing with three different magnetic environments due to strong magnetic field. The AFM measurements indicated that the morphologies of nanostructures of Ph(4)C 60 varied with magnetic enviroments as comparison with that in the absence of magnetic processing. At top position (5.6 T; - 940 T 2 /m) with hypogravity, large spherical nanoclusters (60∼70 nm diameter) were observed as comparion with those (ca. 20 nm diameter) in the absence of magnetic processing. At middle positon (15 T; 0 T 2 /m) with normal gravity, the fiber-like nanostructure was observed. At bottom position (9.8 T; + 1070T 2 /m) with hypergravity, the rod-like nanostrucure was observed. The interesting results might be ascribed to the different solvent properties due to the different rates of evaporation of two solvents in the toluene-acetonitrile mixed solvent during drying process under various magnetic environments. First reduction peaks due to C 60 moiety of Ph(4)C 60 nanostrucures in the presence of magnetic processing at three different positions were negative-shifted as comparison with that in the absence of magnetic processing. Potential dependencies of the photocurrents of the electrodes modified with Ph(4)C 60 nanostrucures in the presence of magnetic processing at three positions were also different from that in the absence of magnetic processing. The magnetic field effects in AFM, and electrochemical and photoelectrochemical measurements are most likely ascribed to the difference of the reduction potentials due to C 60 clusters between the absence and presence of magnetic processing due to the morphological change of Ph(4)C 60 nanostrucures.

  1. Effects of aqueous stable fullerene nanocrystals (nC60) on the food conversion from Daphnia magna to Danio rerio in a simplified freshwater food chain.

    Science.gov (United States)

    Tao, Xianji; Li, Cuilan; Zhang, Bo; He, Yiliang

    2016-02-01

    Understanding the nanomaterial potential to the food conversion of two food chain levels is important in the ecosystem assessment as manufactured nanomaterials are being released into the environment. In this investigation, the food conversion from Daphnia magna (D. magna) (prey) to Danio rerio (D. rerio) (predator) was used as the study object of aqueous stable fullerene nanocrystals (nC60). Accumulated nC60 of D. magna was determined as the nominal initial exposure concentration for D. rerio. The results of 21-d dietary exposure experiment demonstrate that nC60 in D. magna decreased the body weight growths and condition factors of D. rerio, and reduced the food conversion ratio by 20% (from D. magna to D. rerio). Further, the experiments present that nC60 decrease three digestive enzymes activities of trypsinase, lipase, and amylase by 30, 29, and 55% in vivo, and by 60, 90, and 42% in vitro, respectively. Both in vivo and in vitro experiments indicated that nC60 was involved with the decrements of digestive enzymes activities. These decrements in digestive enzymes activities may be due to the deactivation caused by the adsorption of nC60 particles onto the surface or active center of digestive enzymes. Sum up, these results not only describe the nC60 deleterious effects on the food conversion from D. magna to D. rerio, but also provide some information regarding a probable food conversion inhibition mechanism of nC60. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. A statistical approach to inelastic electron tunneling spectroscopy on fullerene-terminated molecules

    DEFF Research Database (Denmark)

    Fock, Jeppe; Sørensen, Jakob Kryger; Lörtscher, Emanuel

    2011-01-01

    We report on the vibrational fingerprint of single C(60) terminated molecules in a mechanically controlled break junction (MCBJ) setup using a novel statistical approach manipulating the junction mechanically to address different molecular configurations and to monitor the corresponding vibration...

  3. Fragment ion distribution in charge-changing collisions of 2-MeV Si ions with C60

    Science.gov (United States)

    Itoh, A.; Tsuchida, H.; Miyabe, K.; Majima, T.; Nakai, Y.

    2001-09-01

    We have measured positive fragment ions produced in collisions of 2 MeV Siq+ (q=0, 1, 2, 4) projectiles with a C60 molecular target. The measurement was performed with a time-of-flight coincidence method between fragment ions and charge-selected outgoing projectiles. For all the charge-changing collisions investigated here, the mass distribution of small fragment ions C+n (n=1-12) can be approximated fairly well by a power-law form of n-λ as a function of the cluster size n. The power λ derived from each mass distribution is found to change strongly according to different charge-changing collisions. As a remarkable experimental finding, the values of λ(loss) in electron loss collisions are almost the same for the same final charge states k irrespective of the initial charge q, exhibiting a nearly perfect linear relationship with k. We also performed calculations of the projectile ionization on the basis of the semiclassical approximation and obtained inelastic energy deposition for individual collision processes. The estimated energy deposition is found to have a simple correlation with the experimentally determined values of λ(loss).

  4. Cluster induced chemistry at solid surfaces: Molecular dynamics simulations of keV C60 bombardment of Si

    International Nuclear Information System (INIS)

    Krantzman, K.D.; Kingsbury, D.B.; Garrison, Barbara J.

    2007-01-01

    Molecular dynamics simulations of the sputtering of Si by keV C 60 bombardment have been performed as a function of incident kinetic energy at two incident angles, normal incidence and 45 deg. Nearly all of the C atoms remain embedded in the surface after bombardment because the C atoms from the projectile form strong covalent bonds with the Si atoms in the target. At low incident kinetic energies, the sputtering yield of Si atoms is small and there is a net deposition of solid material from the projectile atoms. As the incident kinetic energy is increased, the yield of sputtered Si atoms increases. A transition occurs in which the yield of sputtered Si atoms exceeds the number of C atoms deposited, and there is a net erosion of the solid material. A significantly higher sputter yield is observed at an incident angle of 45 deg. than at normal incidence, and therefore, the energy value is lower for the transition from net deposition to net erosion. This phenomenon is discussed in terms of the depth distribution of deposited energy, which is found to be shallower at an incident angle of 45 deg

  5. Photoinduced electron transfer in a Watson-Crick base-paired, 2-aminopurine:uracil-C60 hydrogen bonding conjugate.

    Science.gov (United States)

    D'Souza, Francis; Gadde, Suresh; Islam, D-M Shafiqul; Pang, Siew-Cheng; Schumacher, Amy Lea; Zandler, Melvin E; Horie, Rumiko; Araki, Yasuyaki; Ito, Osamu

    2007-02-07

    A fluorescent reporter molecule, 2-aminopurine was self-assembled via Watson-Crick base-pairing to a uracil appended fullerene to form a donor-acceptor conjugate; efficient photoinduced charge separation was confirmed by time-resolved emission and transient absorption spectral studies.

  6. Mechanochemical Preparation of Stable Sub-100 nm γ-Cyclodextrin:Buckminsterfullerene (C60) Nanoparticles by Electrostatic or Steric Stabilization.

    Science.gov (United States)

    Van Guyse, Joachim F R; de la Rosa, Victor R; Hoogenboom, Richard

    2018-02-21

    Buckminster fullerene (C 60 )'s main hurdle to enter the field of biomedicine is its low bioavailability, which results from its extremely low water solubility. A well-known approach to increase the water solubility of C 60 is by complexation with γ-cyclodextrins. However, the formed complexes are not stable in time as they rapidly aggregate and eventually precipitate due to attractive intermolecular forces, a common problem in inclusion complexes of cyclodextrins. In this study we attempt to overcome the attractive intermolecular forces between the complexes by designing custom γ-cyclodextrin (γCD)-based supramolecular hosts for C 60 that inhibit the aggregation found in native γCD-C 60 complexes. The approach entails the introduction of either repulsive electrostatic forces or increased steric hindrance to prevent aggregation, thus enhancing the biomedical application potential of C 60 . These modifications have led to new sub-100 nm nanostructures that show long-term stability in solution. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Perturbed Angular Correlation Study of the Static and Dynamic Aspects of Cadmium and Mercury Atoms Inside and Attached to a C60 Fullerene Cage

    CERN Document Server

    Das, Satyendra K; Banerjee, Debasish; Johnston, Karl; Das, Parnika; Butz, Tilman; Amaral, Vitor S; Correia, Joao G; Barbosa, Marcelo B

    2014-01-01

    30 keV Cd-111m and 50 keV Hg-199m beams from ISOLDE were used to implant on preformed targets of C-60 with a thickness of 1 mg cm(-2). Endofullerene compounds, viz. Cd-111m@C-60 and Hg-199m@C-60 formed during implantation were separated by filtration through micropore filter paper followed by solvent extraction. Dried samples of the endofullerene compounds were counted for the time differential perturbed angular correlation (TDPAC) measurement using the coincidence of the 151-245 keV cascade of Cd-111m and the 374 158 keV cascade of Hg-199m on a six LaBr3(Ce) detector system coupled with digital electronics. The results for 111mCd@C60 indicate a single static component (27\\%) and a fast relaxing component (73\\%), the latter implying that the cadmium atom moves rapidly inside the cage at room temperature. The quadrupole interaction frequency and asymmetry parameter of the cadmium atom occupying the static site in C60 are omega(Q) = 8.21(36) Mrad s(-1) and eta = 0.41(9), respectively. The fast relaxation con...

  8. Analysis of carrier behavior in C60/P(VDF-TrFE) double-layer capacitor by using electric-field-induced optical second-harmonic generation measurement

    International Nuclear Information System (INIS)

    Cui, Xiaojin; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa

    2013-01-01

    By using displacement current measurement (DCM) and electric-field-induced optical second-harmonic generation (EFISHG) measurement, we studied the carrier behavior in the indium-tin oxide (ITO)/Poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE))/C60/Au(or Al) capacitors. Two DCM peaks appeared asymmetrically at around −35.5 V and +30.0 V in the dark. Correspondingly, the EFISHG response from the C60 layer was observed, but the peak positions were different with respect to DCM ones. The results show that the spontaneous polarization of the ferroelectric P(VDF-TrFE) polymeric layer directly affects the electric field in the C60 layer, and thus governs the carrier motion in this layer. As a result, the C60 layer serves like an insulator in the dark, while electrons and holes are captured and released at the interface in response to the turn-over of spontaneous polarization of ferroelectric layer. On the other hand, under white light illumination, C60 layer serves like a conductor due to the increase of photogenerated mobile carriers, and these carriers dominate the carrier motions therein. Our findings here will be helpful for analyzing carrier behaviors in organic electronic devices using ferroelectric polymers

  9. Analysis of carrier behavior in C60/P(VDF-TrFE) double-layer capacitor by using electric-field-induced optical second-harmonic generation measurement

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Xiaojin [Department of Physical Electronics, Tokyo Institute of Technology 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan); State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa, E-mail: iwamoto@pe.titech.ac.jp [Department of Physical Electronics, Tokyo Institute of Technology 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan)

    2013-12-21

    By using displacement current measurement (DCM) and electric-field-induced optical second-harmonic generation (EFISHG) measurement, we studied the carrier behavior in the indium-tin oxide (ITO)/Poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE))/C60/Au(or Al) capacitors. Two DCM peaks appeared asymmetrically at around −35.5 V and +30.0 V in the dark. Correspondingly, the EFISHG response from the C60 layer was observed, but the peak positions were different with respect to DCM ones. The results show that the spontaneous polarization of the ferroelectric P(VDF-TrFE) polymeric layer directly affects the electric field in the C60 layer, and thus governs the carrier motion in this layer. As a result, the C60 layer serves like an insulator in the dark, while electrons and holes are captured and released at the interface in response to the turn-over of spontaneous polarization of ferroelectric layer. On the other hand, under white light illumination, C60 layer serves like a conductor due to the increase of photogenerated mobile carriers, and these carriers dominate the carrier motions therein. Our findings here will be helpful for analyzing carrier behaviors in organic electronic devices using ferroelectric polymers.

  10. Modeling adsorption of brominated, chlorinated and mixed bromo/chloro-dibenzo-p-dioxins on C60 fullerene using Nano-QSPR

    Directory of Open Access Journals (Sweden)

    Piotr Urbaszek

    2017-03-01

    Full Text Available Many technological implementations in the field of nanotechnology have involved carbon nanomaterials, including fullerenes such as the buckminsterfullerene, C60. The unprecedented properties of such organic nanomaterials (in particular their large surface area gained extensive attention for their potential use as organic pollutant sorbents. Sorption interactions can be very hazardous and useful at the same time. This work investigates the influence of halogenation by bromine and/or chlorine in dibenzo-p-dioxins on their sorption ability on the C60 fullerene surface. Halogenated dibenzo-p-dioxins (PXDDs, where X = Br or Cl are ever-present in the environment and accidently produced in many technological processes in only approximately known quantities. If all combinatorial Br and/or Cl dioxin substitution possibilities are present in the environment, the experimental characterization and investigation of sorbent effectiveness is more than difficult. In this work, we have developed a quantitative structure–property relationship (QSPR model (R2 = 0.998, predicting the adsorption energy [kcal/mol] for 1,701 PXDDs adsorbed on C60 (PXDD@C60. Based on the QSPR model reported herein, we concluded that the lowest energy PXDD@C60 complexes are those that the World Health Organization (WHO considers to be less dangerous with respect to the aryl hydrocarbon receptor (AhR toxicity mechanism. Therefore, the effectiveness of fullerenes as sorbent agents may be underestimated as sorption could be less effective for toxic congeners than previously believed.

  11. Preparation and Preliminary Dielectric Characterization of Structured C60-Thiol-Ene Polymer Nanocomposites Assembled Using the Thiol-Ene Click Reaction

    Directory of Open Access Journals (Sweden)

    Hanaa M. Ahmed

    2015-11-01

    Full Text Available Fullerene-containing materials have the ability to store and release electrical energy. Therefore, fullerenes may ultimately find use in high-voltage equipment devices or as super capacitors for high electric energy storage due to this ease of manipulating their excellent dielectric properties and their high volume resistivity. A series of structured fullerene (C60 polymer nanocomposites were assembled using the thiol-ene click reaction, between alkyl thiols and allyl functionalized C60 derivatives. The resulting high-density C60-urethane-thiol-ene (C60-Thiol-Ene networks possessed excellent mechanical properties. These novel networks were characterized using standard techniques, including infrared spectroscopy (FTIR, differential scanning calorimetry (DSC, dynamic mechanical analysis (DMA, and thermal gravimetric analysis (TGA. The dielectric spectra for the prepared samples were determined over a broad frequency range at room temperature using a broadband dielectric spectrometer and a semiconductor characterization system. The changes in thermo-mechanical and electrical properties of these novel fullerene-thiol-ene composite films were measured as a function of the C60 content, and samples characterized by high dielectric permittivity and low dielectric loss were produced. In this process, variations in chemical composition of the networks were correlated to performance characteristics.

  12. Bias voltage dependence of tunneling magnetoresistance in granular C60–Co films with current-perpendicular-to-plane geometry

    International Nuclear Information System (INIS)

    Sakai, Seiji; Mitani, Seiji; Matsumoto, Yoshihiro; Entani, Shiro; Avramov, Pavel; Ohtomo, Manabu; Naramoto, Hiroshi; Takanashi, Koki

    2012-01-01

    Voltage-dependence of the tunneling magnetoresistance effect in the granular C 60 –Co films has been investigated for the samples with the current-perpendicular-to-plane geometry. The transport measurements under this geometry demonstrate that the granular C 60 –Co films show an unusual exponential bias voltage dependence of the magnetoresistance ratio down to zero voltage. Small characteristic energies of less than 10's meV are derived from the temperature dependences of the characteristic voltage in the exponential relationship. Considering the magnitudes of the voltage drop between Co nanoparticles and also the effect of cotunneling on the energy values, the characteristic energies for the voltage-induced degradation of the spin polarization are found to show a satisfactory agreement with that for the thermally-induced one. It can be reasonably expected that the onset of magnetic disorder to the localized d-electron spins at the interface region of the C 60 -based matrix (C 60 –Co compound) with Co nanoparticles leading to the unusual voltage and temperature dependence of the magnetoresistance ratio and the spin polarization at low temperatures. - Highlights: ► Unusual voltage dependence of the TMR effect in granular C 60 –Co films is studied. ► Linear temperature-characteristic voltage dependence in the MR–V relationship. ► Spin-flip scattering by the exchange-coupled d-electron spins at the interface.

  13. Characterisation of human hair surfaces by means of static ToF-SIMS: A comparison between Ga+ and C60+ primary ions

    International Nuclear Information System (INIS)

    Poleunis, Claude; Everaert, Emmanuel P.; Delcorte, Arnaud; Bertrand, Patrick

    2006-01-01

    This study deals with the secondary ion yield improvement induced by using C 60 + primary ions instead of Ga + ones to characterize human hair surfaces by ToF-SIMS. For that purpose, a bunch of hair fibres has been analysed with both ion sources. A high improvement is observed for the detection of amino acids with C 60 + primary ions as compared to Ga + ions. As an example, a yield enhancement factor greater than 3000 is found for the CNO - peak. A similar gain is observed for the positive secondary ions characteristic of the amino acids. Most of the atomic ions, such as Ca + , O - and S - , constitute minor peaks with C 60 + ions while they often dominate the spectrum in the case of Ga + ions. However, with the C 60 + source, a series of inorganic combination peaks with the elements Ca, S and O are observed in the positive spectra (i.e. HCaSO 4 + ), while they are marginal with the Ga + source. For the mass range beyond 100 m/z and in both polarities, the hair fingerprints are similar with both sources. In average, for a comparable number of primary ions per spectrum, the C 60 + ion source gives intensities between two and three orders of magnitude higher than the Ga + one

  14. Intraperitoneal Exposure to Nano/Microparticles of Fullerene (C60) Increases Acetylcholinesterase Activity and Lipid Peroxidation in Adult Zebrafish (Danio rerio) Brain

    Science.gov (United States)

    Dal Forno, Gonzalo Ogliari; Kist, Luiza Wilges; de Azevedo, Mariana Barbieri; Fritsch, Rachel Seemann; Pereira, Talita Carneiro Brandão; Britto, Roberta Socoowski; Guterres, Sílvia Stanisçuaski; Külkamp-Guerreiro, Irene Clemes; Bonan, Carla Denise; Monserrat, José María; Bogo, Maurício Reis

    2013-01-01

    Even though technologies involving nano/microparticles have great potential, it is crucial to determine possible toxicity of these technological products before extensive use. Fullerenes C60 are nanomaterials with unique physicochemical and biological properties that are important for the development of many technological applications. The aim of this study was to evaluate the consequences of nonphotoexcited fullerene C60 exposure in brain acetylcholinesterase expression and activity, antioxidant responses, and oxidative damage using adult zebrafish as an animal model. None of the doses tested (7.5, 15, and 30 mg/kg) altered AChE activity, antioxidant responses, and oxidative damage when zebrafish were exposed to nonphotoexcited C60 nano/microparticles during 6 and 12 hours. However, adult zebrafish exposed to the 30 mg/kg dose for 24 hours have shown enhanced AChE activity and augmented lipid peroxidation (TBARS assays) in brain. In addition, the up-regulation of brain AChE activity was neither related to the transcriptional control (RT-qPCR analysis) nor to the direct action of nonphotoexcited C60 nano/microparticles on the protein (in vitro results) but probably involved a posttranscriptional or posttranslational modulation of this enzymatic activity. Taken together these findings provided further evidence of toxic effects on brain after C60 exposure. PMID:23865059

  15. Transport properties of field-effect transistor with Langmuir-Blodgett films of C60 dendrimer and estimation of impurity levels

    Science.gov (United States)

    Kawasaki, Naoko; Nagano, Takayuki; Kubozono, Yoshihiro; Sako, Yuuki; Morimoto, Yu; Takaguchi, Yutaka; Fujiwara, Akihiko; Chu, Chih-Chien; Imae, Toyoko

    2007-12-01

    Field-effect transistor (FET) device has been fabricated with Langmuir-Blodgett films of C60 dendrimer. The device showed n-channel normally off characteristics with the field-effect mobility of 2.7×10-3cm2V-1s-1 at 300K, whose value is twice as high as that (1.4×10-3cm2V-1s-1) for the FET with spin-coated films of C60 dendrimer. This originates from the formation of ordered π-conduction network of C60 moieties. From the temperature dependence of field-effect mobility, a structural phase transition has been observed at around 300K. Furthermore, the density of states for impurity levels was estimated in the Langmuir-Blodgett films.

  16. A direct investigation of photocharge transfer across monomolecular layer between C60 and CdS quantum dots by photoassisted conductive atomic force microscopy

    Directory of Open Access Journals (Sweden)

    Xiaohong Jiang

    2016-04-01

    Full Text Available The composite assembly of C60 and CdS Quantum Dots (QDs on ITO substrate was prepared by Langmuir-Blodgett (LB technique using arachic acid (AA, stearic acid (SA and octadecanyl amine (OA as additives. Photoassisted conductive atomic force microscopy was used to make point contact current-voltage (I-V measurements on both the CdS QDs and the composite assembly of C60/CdS. The result make it clear that the CdS, C60/CdS assemblies deposited on ITO substrate showed linear characteristics and the current increased largely under illumination comparing with that in the dark. The coherent, nonresonant tunneling mechanism was used to explain the current occurrence. It is considered that the photoinduced carriers CdS QDs tunneled through alkyl chains increased the current rapidly.

  17. Modest vasomotor dysfunction induced by low doses of C60 fullerenes in apolipoprotein E knockout mice with different degree of atherosclerosis

    Directory of Open Access Journals (Sweden)

    Loft Steffen

    2009-02-01

    Full Text Available Abstract Background Exposure to small size particulate matter in urban air is regarded as a risk factor for cardiovascular effects, whereas there is little information about the impact on the cardiovascular system by exposure to pure carbonaceous materials in the nano-size range. C60 fullerenes are nano-sized particles that are expected to have a widespread use, including cosmetics and medicines. Methods We investigated the association between intraperitoneal injection of pristine C60 fullerenes and vasomotor dysfunction in the aorta of 11–13 and 40–42 weeks old apolipoprotein E knockout mice (apoE-/- with different degree of atherosclerosis. Results The aged apoE-/-mice had lower endothelium-dependent vasorelaxation elicited by acetylcholine in aorta segments mounted in myographs and the phenylephrine-dependent vasoconstriction response was increased. One hour after an intraperitoneal injection of 0.05 or 0.5 mg/kg of C60 fullerenes, the young apoE-/- mice had slightly reduced maximal endothelium-dependent vasorelaxation. A similar tendency was observed in the old apoE-/- mice. Hampered endothelium-independent vasorelaxation was also observed as slightly increased EC50 of sodium nitroprusside-induced vasorelaxation response in young apoE-/- mice. Conclusion Treatment with C60 fullerenes affected mainly the response to vasorelaxation in young apoE-/- mice, whereas the vasomotor dysfunction in old apoE-/- mice with more advanced atherosclerosis was less affected by acute C60 fullerene treatment. These findings represent an important step in the hazard characterization of C60 fullerenes by showing that intraperitoneal administration is associated with a moderate decrease in the vascular function of mice with atherosclerosis.

  18. Electrochemical, spectroscopic, and DFT study of C60(CF3)n frontier orbitals (n = 2-18): the link between double bonds in pentagons and reduction potentials.

    Science.gov (United States)

    Popov, Alexey A; Kareev, Ivan E; Shustova, Natalia B; Stukalin, Evgeny B; Lebedkin, Sergey F; Seppelt, Konrad; Strauss, Steven H; Boltalina, Olga V; Dunsch, Lothar

    2007-09-19

    The frontier orbitals of 22 isolated and characterized C(60)(CF(3))(n) derivatives, including seven reported here for the first time, have been investigated by electronic spectroscopy (n = 2 [1], 4 [1], 6 [2], 8 [5], 10 [6], 12 [3]; the number of isomers for each composition is shown in square brackets) fluorescence spectroscopy (n = 10 [4]), cyclic voltammetry under air-free conditions (all compounds with n mV s(-1) up to 5.0 V s(-1), respectively. The 18 experimental 0/- E(1/2) values (vs C(60)(0/-)) are a linear function of the DFT-predicted LUMO energies (average E1/2 deviation from the least-squares line is 0.02 V). This linear relationship was used to predict the 0/- E(1/2) values for the n = 16 and 18 derivatives, and none of the predicted values is more positive than the 0/- E(1/2) value for one of the isomers of C(60)(CF(3))(10). In general, reduction potentials for the 0/- couple are shifted anodically relative to the C(60)(0/-) couple. However, the 0/- E(1/2) values for a given composition are strongly dependent on the addition pattern of the CF3 groups. In addition, LUMO energies for isomers of C(60)(X)(n) (n = 2, 4, 6, 8, 10, and 12) that are structurally related to many of the CF(3) derivatives were calculated and compared for X = CH(3), H, Ph, NH(2), CH(2)F, CHF(2), F, NO(2), and CN. The experimental and computational results for the C(60)(CF(3))(n) compounds and the computational results for more than 50 additional C(60)(X)(n) compounds provide new insights about the frontier orbitals of C(60)(X)(n) derivatives. For a given substituent, X, the addition pattern is as important, if not more important in many cases, than the number of substituents, n, in determining E(1/2) values. Those addition patterns with double bonds in pentagons having two C(sp(2)) nearest neighbors result in the strongest electron acceptors.

  19. Molecule nanoweaver

    Science.gov (United States)

    Gerald, II; Rex, E [Brookfield, IL; Klingler, Robert J [Glenview, IL; Rathke, Jerome W [Homer Glen, IL; Diaz, Rocio [Chicago, IL; Vukovic, Lela [Westchester, IL

    2009-03-10

    A method, apparatus, and system for constructing uniform macroscopic films with tailored geometric assemblies of molecules on the nanometer scale. The method, apparatus, and system include providing starting molecules of selected character, applying one or more force fields to the molecules to cause them to order and condense with NMR spectra and images being used to monitor progress in creating the desired geometrical assembly and functionality of molecules that comprise the films.

  20. Electronic Spectroscopy of Organic Cations in Gas-Phase at 6 K:IDENTIFICATION of C60/^+ in the Interstellar Medium

    Science.gov (United States)

    Maier, John P.

    2016-06-01

    After the discovery of C60, the question of its relevance to the diffuse interstellar bands was raised. In 1987 H. W. Kroto wrote: ``The present observations indicate that C60 might survive in the general interstellar medium (probably as the ion C60/^+)''. In 1994 two diffuse interstellar bands (DIBs) at 9632 and 9577 Å/ were detected and proposed to be the absorption features of C60/^+. This was based on the proximity of these wavelengths to the two prominent absorption bands of C60/^+ measured by us in a neon matrix in 1993. Confirmation of the assignment required the gas phase spectrum of C60/^+ and has taken 20 years. The approach which succeeded confines C60/^+ ions in a radiofrequency trap, cools them by collisions with high density helium allowing formation of the weakly bound C60/^+--He complexes below 10 K. The photofragmentation spectrum of this mass-selected complex is then recorded using a cw laser. In order to infer the position of the absorption features of the bare C60/^+ ion, measurements on C60/^+--He_2 were also made. The spectra show that the presence of a helium atom shifts the absorptions by less than 0.2 Å, much less than the accuracy of the astronomical measurements. The two absorption features in the laboratory have band maxima at 9632.7(1) and 9577.5(1) Å, exactly the DIB wavelengths, and the widths and relative intensities agree. This leads to the first definite identification of now five bands among the five hundred or so DIBs known and proves the presence of gaseous C60/^+ in the interstellar medium. The absorption of cold C70/^+ has also been obtained by this approach. In addition the electronic spectra of a number of cations of astrophysical interest ranging from those of carbon chains including oxygen to larger polycyclic aromatic hydrocarbon could be measured in the gas phase at around 10 K in the ion trap but using an excitation-dissociation approach. The implications of these laboratory spectra in relation to the diffuse

  1. Incorporating C60 as Nucleation Sites Optimizing PbI2 Films To Achieve Perovskite Solar Cells Showing Excellent Efficiency and Stability via Vapor-Assisted Deposition Method.

    Science.gov (United States)

    Chen, Hai-Bin; Ding, Xi-Hong; Pan, Xu; Hayat, Tasawar; Alsaedi, Ahmed; Ding, Yong; Dai, Song-Yuan

    2018-01-24

    To achieve high-quality perovskite solar cells (PSCs), the morphology and carrier transportation of perovskite films need to be optimized. Herein, C 60 is employed as nucleation sites in PbI 2 precursor solution to optimize the morphology of perovskite films via vapor-assisted deposition process. Accompanying the homogeneous nucleation of PbI 2 , the incorporation of C 60 as heterogeneous nucleation sites can lower the nucleation free energy of PbI 2 , which facilitates the diffusion and reaction between PbI 2 and organic source. Meanwhile, C 60 could enhance carrier transportation and reduce charge recombination in the perovskite layer due to its high electron mobility and conductivity. In addition, the grain sizes of perovskite get larger with C 60 optimizing, which can reduce the grain boundaries and voids in perovskite and prevent the corrosion because of moisture. As a result, we obtain PSCs with a power conversion efficiency (PCE) of 18.33% and excellent stability. The PCEs of unsealed devices drop less than 10% in a dehumidification cabinet after 100 days and remain at 75% of the initial PCE during exposure to ambient air (humidity > 60% RH, temperature > 30 °C) for 30 days.

  2. Stability and delayed fragmentation of highly charged C60 trapped in a conic-electrode electrostatic ion resonator (ConeTrap)

    International Nuclear Information System (INIS)

    Bernard, J.; Wei, B.; Bourgey, A.; Bredy, R.; Chen, L.; Kerleroux, M.; Martin, S.; Montagne, G.; Salmoun, A.; Terpend-Ordaciere, B.

    2007-01-01

    We employed a conic-electrode electrostatic ion resonator (ConeTrap) to store the recoil ions (C 60 r+ ) resulting from collision between 56keV Ar 8+ ions and C 60 in order to study their stability over a long time range (several milliseconds). The originality of our method, based on the trapping of a single ion to preserve the detection in coincidence of all the products of the collision, is presented in detail. Our results show that C 60 ions produced in such collisions are stable in the considered observation time. By employing the ConeTrap as a secondary mass spectrometer in order to let the ions oscillate only for a single period, we have been able to observe delayed evaporation of cold C 60 3+ ions 20μs after the collision. We interpret quantitatively the relative yields of daughter ions with a cascade model in which the transition rates are estimated via the commonly used Arrhenius law, taking into account the contribution of the radiative decay

  3. The influence hydrogen atom addition has on charge switching during motion of the metal atom in endohedral Ca@C60H4 isomers

    Science.gov (United States)

    Raggi, G.; Besley, E.; Stace, A. J.

    2016-01-01

    Density functional theory has been applied in a study of charge transfer between an endohedral calcium atom and the fullerene cage in Ca@C60H4 and [Ca@C60H4]+ isomers. Previous calculations on Ca@C60 have shown that the motion of calcium within a fullerene is accompanied by large changes in electron density on the carbon cage. Based on this observation, it has been proposed that a tethered endohedral fullerene might form the bases of a nanoswitch. Through the addition of hydrogen atoms to one hemisphere of the cage it is shown that, when compared with Ca@C60, asymmetric and significantly reduced energy barriers can be generated with respect to motion of the calcium atom. It is proposed that hydrogen atom addition to a fullerene might offer a route for creating a bi-stable nanoswitch that can be fine-tuned through the selection of an appropriate isomer and number of atoms attached to the cage of an endohedral fullerene. This article is part of the themed issue ‘Fullerenes: past, present and future, celebrating the 30th anniversary of Buckminster Fullerene’. PMID:27501967

  4. Diels-Alders adducts of C-60 and esters of 3-(1-indenyl)-propionic acid : alternatives for [60]PCBM in polymer:fullerene solar cells

    NARCIS (Netherlands)

    Sieval, Alexander B.; Treat, Neil D.; Rozema, Desiree; Hummelen, Jan C.; Stingelin, Natalie

    2015-01-01

    A series of new, easily synthesized C-60-fullerene derivatives is introduced that allow for optimization of the interactions between rr-P3HT and the fullerene by systematic variation of the size of the ester group. Two compounds gave overall cell efficiencies of 4.8%, clearly outperforming [60]PCBM

  5. Description of the Charge Transfer States at the Pentacene/C60 Interface: Combining Range-Separated Hybrid Functionals with the Polarizable Continuum Model

    KAUST Repository

    Zheng, Zilong; Bredas, Jean-Luc; Coropceanu, Veaceslav

    2016-01-01

    are usually performed on small-size donor/acceptor complexes and as result do not account for electronic polarization effects. Here, using a pentacene/C60 complex as a model system, we discuss the ability of long-range corrected (LCR) hybrid functionals

  6. Film morphology effects on the electrical and optical properties of bulk heterojunction organic solar cells based on MEH-PPV/C60 composite

    International Nuclear Information System (INIS)

    Ltaief, A.; Davenas, J.; Bouazizi, A.; Ben Chaabane, R.; Alcouffe, P.; Ben Ouada, H.

    2005-01-01

    The influence of film morphology on the electrical behaviour of an MEH-PPV/C 60 organic solar cells has been investigated. The dissociation of photogenerated charge pairs in composites of buckminsterfullerenes (C 60 ) in a conjugated polymer matrix (MEH-PPV) forming dispersed heterojunctions was studied at low C 60 acceptor concentrations to separate electron transfer from charge transport effects. The motivation of this study was to analyse the strong dependence of organic solar cell efficiencies on the morphology of the composite. Two effects controlling film morphology have been investigated; the first one being the influence of the fullerene concentration and the second one is the effect of the organic solvent used to deposit the photoactive layer. The sample morphology was studied using atomic force microscopy (AFM). Photoluminescence (PL) experiments and current-voltage (I-V) measurements were performed on the deposited photovoltaic film to investigate the influence of dispersion on the charge transfer process between MEH-PPV and C 60 . An attempt to explain all the results will be presented

  7. Quantum plasmon and Rashba-like spin splitting in self-assembled Co x C60 composites with enhanced Co content (x > 15)

    Science.gov (United States)

    Lavrentiev, Vasily; Chvostova, Dagmar; Stupakov, Alexandr; Lavrentieva, Inna; Vacik, Jiri; Motylenko, Mykhaylo; Barchuk, Mykhailo; Rafaja, David; Dejneka, Alexandr

    2018-04-01

    Driving by interplay between plasmonic and magnetic effects in organic composite semiconductors is a challenging task with a huge potential for practical applications. Here, we present evidence of a quantum plasmon excited in the self-assembled Co x C60 nanocomposite films with x > 15 (interval of the Co cluster coalescence) and analyse it using the optical absorption (OA) spectra. In the case of Co x C60 film with x = 16 (LF sample), the quantum plasmon generated by the Co/CoO clusters is found as the 1.5 eV-centred OA peak. This finding is supported by the establishment of four specific C60-related OA lines detected at the photon energies E p > 2.5 eV. Increase of the Co content up to x = 29 (HF sample) leads to pronounced enhancement of OA intensity in the energy range of E p > 2.5 eV and to plasmonic peak downshift of 0.2 eV with respect to the peak position in the LF spectrum. Four pairs of the OA peaks evaluated in the HF spectrum at E p > 2.5 eV reflect splitting of the C60-related lines, suggesting great change in the microscopic conditions with increasing x. Analysis of the film nanostructure and the plasmon-induced conditions allows us to propose a Rashba-like spin splitting effect that suggests valuable sources for spin polarization.

  8. High-precision measurement of the electron spin g factor of trapped atomic nitrogen in the endohedral fullerene N@C60

    Science.gov (United States)

    Wittmann, J. J.; Can, T. V.; Eckardt, M.; Harneit, W.; Griffin, R. G.; Corzilius, B.

    2018-05-01

    The electronic g factor carries highly useful information about the electronic structure of a paramagnetic species, such as spin-orbit coupling and dia- or paramagnetic (de-)shielding due to local fields of surrounding electron pairs. However, in many cases, a near "spin-only" case is observed, in particular for light elements, necessitating accurate and precise measurement of the g factors. Such measurement is typically impeded by a "chicken and egg situation": internal or external reference standards are used for relative comparison of electron paramagnetic resonance (EPR) Larmor frequencies. However, the g factor of the standard itself usually is subject to a significant uncertainty which directly limits the precision and/or accuracy of the sought after sample g factor. Here, we apply an EPR reference-free approach for determining the g factor of atomic nitrogen trapped within the endohedral fullerene C60:N@C60 in its polycrystalline state by measuring the 1H NMR resonance frequency of dispersing toluene at room temperature. We found a value of g = 2.00204 (4) with a finally reached relative precision of ∼20 ppm. This accurate measurement allows us to directly compare the electronic properties of N@C60 to those found in atomic nitrogen in the gas phase or trapped in other solid matrices at liquid helium temperature. We conclude that spin-orbit coupling in N@C60 at room temperature is very similar in magnitude and of same sign as found in other inert solid matrices and that interactions between the quartet spin system and the C60 molecular orbitals are thus negligible.

  9. Activation of store – operated Ca(2+ entry in cisplatin resistant leukemic cells after treatment with photoexcited fullerene C(60 and cisplatin

    Directory of Open Access Journals (Sweden)

    D. V. Franskevych

    2018-04-01

    Full Text Available Ca2+-regulating system in cancer cells is suggested to be remodulated particularly by reduced store-operated Ca2+ entry (SOCE through plasma membrane in order to maintain moderately reduced cytosolic Ca2+ concentration and to avoid apoptosis. The endoplasmic reticulum (ER Ca2+ pool content and the size of SOCE in leukemic wild type (L1210 and resistant to cisplatin (L1210R cells in control, after treatment with either cisplatin (1 µg/ml or photoexcited fulleren C60 (10-5 M alone, or their combination were estimated with the use of Indo-1 AM. The SOCE in resistant to cisplatin L1210R cells was found to be lower than in the wild-type cells. After treatment with cisplatin the decrease of thapsigargin (TG-sensitive ER Ca2+ pool with no significant increase of SOCE was observed in L1210 cells, while no changes were detected in L1210R cells. Photoexcitation of intracellular accumulated fullerene C60 in the visible range of spectrum (410-700 nm was accompanied by increase of SOCE not only in sensitive, but in resistant cells as well. In resistant L1210R cells treated with photoexcited C60 essential effect of cisplatin on Ca2+ homeostasis became obvious: the size of SOCE proved to be higher than after treatment with photoexcited C60 alone. The data obtained allow suggesting­ the influence of photoexcited C60 not only on Ca2+-regulating system, but on those involved in controlling cisplatin entry into drug resistant cancer cells.

  10. Molecule Matters

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 4. Molecule Matters – van der Waals Molecules - History and Some Perspectives on Intermolecular Forces. E Arunan. Feature Article Volume 14 Issue 4 April 2009 pp 346-356 ...

  11. Conceptual modeling for identification of worst case conditions in environmental risk assessment of nanomaterials using nZVI and C60 as case studies

    DEFF Research Database (Denmark)

    Grieger, Khara Deanne; Hansen, Steffen Foss; Sørensen, Peter B.

    2011-01-01

    , especially given the vast variety and complexity of nanomaterials and their applications. As an approach to help optimize environmental risk assessments of nanomaterials, we apply the Worst-Case Definition (WCD) model to identify best estimates for worst-case conditions of environmental risks of two case......Conducting environmental risk assessment of engineered nanomaterials has been an extremely challenging endeavor thus far. Moreover, recent findings from the nano-risk scientific community indicate that it is unlikely that many of these challenges will be easily resolved in the near future...... studies which use engineered nanoparticles, namely nZVI in soil and groundwater remediation and C60 in an engine oil lubricant. Results generated from this analysis may ultimately help prioritize research areas for environmental risk assessments of nZVI and C60 in these applications as well as demonstrate...

  12. Semigroups of transcendental entire functions and their dynamics

    Indian Academy of Sciences (India)

    DINESH KUMAR

    Abstract. We investigate the dynamics of semigroups of transcendental entire func- tions using Fatou–Julia theory. Several results of the dynamics associated with iteration of a transcendental entire function have been extended to transcendental semigroups. We provide some condition for connectivity of the Julia set of the ...

  13. Entire solutions of nonlinear differential-difference equations.

    Science.gov (United States)

    Li, Cuiping; Lü, Feng; Xu, Junfeng

    2016-01-01

    In this paper, we describe the properties of entire solutions of a nonlinear differential-difference equation and a Fermat type equation, and improve several previous theorems greatly. In addition, we also deduce a uniqueness result for an entire function f(z) that shares a set with its shift [Formula: see text], which is a generalization of a result of Liu.

  14. Electronic Structure of C60/Zinc Phthalocyanine/V2O5 Interfaces Studied Using Photoemission Spectroscopy for Organic Photovoltaic Applications

    Directory of Open Access Journals (Sweden)

    Chang Jin Lim

    2018-02-01

    Full Text Available The interfacial electronic structures of a bilayer of fullerene (C60 and zinc phthalocyanine (ZnPc grown on vanadium pentoxide (V2O5 thin films deposited using radio frequency sputtering under various conditions were studied using X-ray and ultraviolet photoelectron spectroscopy. The energy difference between the highest occupied molecular orbital (HOMO level of the ZnPc layer and the lowest unoccupied molecular orbital (LUMO level of the C60 layer was determined and compared with that grown on an indium tin oxide (ITO substrate. The energy difference of a heterojunction on all V2O5 was found to be 1.3~1.4 eV, while that on ITO was 1.1 eV. This difference could be due to the higher binding energy of the HOMO of ZnPc on V2O5 than that on ITO regardless of work functions of the substrates. We also determined the complete energy level diagrams of C60/ZnPc on V2O5 and ITO.

  15. Passivating ZnO Surface States by C60 Pyrrolidine Tris-Acid for Hybrid Solar Cells Based on Poly(3-hexylthiophene/ZnO Nanorod Arrays

    Directory of Open Access Journals (Sweden)

    Peng Zhong

    2017-12-01

    Full Text Available Construction of ordered electron acceptors is a feasible way to solve the issue of phase separation in polymer solar cells by using vertically-aligned ZnO nanorod arrays (NRAs. However, the inert charge transfer between conducting polymer and ZnO limits the performance enhancement of this type of hybrid solar cells. In this work, a fullerene derivative named C60 pyrrolidine tris-acid is used to modify the interface of ZnO/poly(3-hexylthiophene (P3HT. Results indicate that the C60 modification passivates the surface defects of ZnO and improves its intrinsic fluorescence. The quenching efficiency of P3HT photoluminescence is enhanced upon C60 functionalization, suggesting a more efficient charge transfer occurs across the modified P3HT/ZnO interface. Furthermore, the fullerene modified hybrid solar cell based on P3HT/ZnO NRAs displays substantially-enhanced performance as compared to the unmodified one and the devices with other modifiers, which is contributed to retarded recombination and enhanced exciton separation as evidenced by electrochemical impedance spectra. Therefore, fullerene passivation is a promising method to ameliorate the connection between conjugated polymers and metal oxides, and is applicable in diverse areas, such as solar cells, transistors, and light-emitting dioxides.

  16. Unraveling current hysteresis effects in regular-type C60-CH3NH3PbI3 heterojunction solar cells.

    Science.gov (United States)

    Chen, Lung-Chien; Lin, Yu-Shiang; Tang, Po-Wen; Tai, Chao-Yi; Tseng, Zong-Liang; Lin, Ja-Hon; Chen, Sheng-Hui; Kuo, Hao-Chung

    2017-11-23

    Comprehensive studies were carried out to understand the origin of the current hysteresis effects in highly efficient C 60 -CH 3 NH 3 PbI 3 (MAPbI 3 ) heterojunction solar cells, using atomic-force microscopy, transmittance spectra, photoluminescence spectra, X-ray diffraction patterns and a femtosecond time-resolved pump-probe technique. The power conversion efficiency (PCE) of C 60 -MAPbI 3 solar cells can be increased to 18.23% by eliminating the point (lattice) defects in the MAPbI 3 thin film which is fabricated by using the one-step spin-coating method with toluene washing treatment. The experimental results show that the point defects and surface defects of the MAPbI 3 thin films can be minimized by varying the dropping time of the washing solvent. The point defects (surface defects) can be reduced with an (a) increase (decrease) in the dropping time, resulting in an optimized dropping time for obtaining the defect-minimized MAPbI 3 thin film deposited on top of the C 60 thin film. Consequently, the formation of the defect-minimized MAPbI 3 thin film allows for high-efficiency MAPbI 3 solar cells.

  17. Impact of C 60 fullerene on the dynamics of force-speed changes in soleus muscle of rat at ischemia-reperfusion injury.

    Science.gov (United States)

    Nozdrenko, D M; Bogutska, K I; Prylutskyy, Yu I; Korolovych, V F; Evstigneev, M P; Ritter, U; Scharff, P

    2015-01-01

    The effect of C60 fullerene nanoparticles (30-90 nm) on dynamics of force response development to stimulated soleus muscle of rat with ischemic pathology, existing in muscle during the first 5 hours and first 5 days after 2 hours of ischemia and further reperfusion, was investigated using the tensometric method. It was found that intravenous and intramuscular administration of C60 fullerene with a single dose of 1 mg/kg exert different therapeutic effects dependent on the investigated macroparameters of muscle contraction. The intravenous drug administration was shown to be the most optimal for correction of the velocity macroparameters of contraction due to muscle tissue ischemic damage. In contrast, the intramuscular administration displays protective action with respect to motions associated with generation of maximal force response or continuous contractions elevating the level of muscle fatigue. Hence, C60 fullerene, being a strong antioxidant, may be considered as a promising agent for effective therapy of pathological states of the muscle system caused by pathological action of free radical processes.

  18. Cyclovoltammetric acetylcholinesterase activity assay after inhibition and subsequent reactivation by using a glassy carbon electrode modified with palladium nanorods composited with functionalized C60 fullerene

    International Nuclear Information System (INIS)

    Ye, Cui; Zhong, Xia; Chai, Yaqin; Yuan, Ruo; Wang, Min-Qiang

    2016-01-01

    A glassy carbon electrode (GCE) was modified with a nanocomposite consisting of tetraoctylammonium bromide (TOAB), C 60 fullerene, and palladium nanorods (PdNRs). The PdNRs were hydrothermally prepared and had a typical width of 20 ± 2 nm. The nanocomposite forms stable films on the GCE and exhibits a reversible redox pair for the C 60 /C 60 − system while rendering the surface to be positively charged. The modified GCE was applied to fabricate an electrochemical biosensor for detecting acetylcholinesterase (AChE) by measurement of the amount of thiocholine formed from acetylthiocholine, best at a working voltage of −0.19 V (vs. SCE). The detection scheme is based on (a) measurement of the activity of ethyl paraoxon-inhibited AChE, and (b) measurement of AChE activity after reactivation with pralidoxime (2-PAM). Compared to the conventional methods using acetylthiocholine as a substrate, the dual method presented here provides data on the AChE activity after inhibition and subsequent reactivation, thereby yielding credible data on reactivated enzyme activity. The linear analytical range for AChE activity extends from 2.5 U L −1 to 250 kU·L −1 , and the detection limit is 0.83 U L −1 . (author)

  19. Diffusion-controlled growth of molecular heterostructures: fabrication of two-, one-, and zero-dimensional C(60) nanostructures on pentacene substrates.

    Science.gov (United States)

    Breuer, Tobias; Witte, Gregor

    2013-10-09

    A variety of low dimensional C60 structures has been grown on supporting pentacene multilayers. By choice of substrate temperature during growth the effective diffusion length of evaporated fullerenes and their nucleation at terraces or step edges can be precisely controlled. AFM and SEM measurements show that this enables the fabrication of either 2D adlayers or solely 1D chains decorating substrate steps, while at elevated growth temperature continuous wetting of step edges is prohibited and instead the formation of separated C60 clusters pinned at the pentacene step edges occurs. Remarkably, all structures remain thermally stable at room temperature once they are formed. In addition the various fullerene structures have been overgrown by an additional pentacene capping layer. Utilizing the different probe depth of XRD and NEXAFS, we found that no contiguous pentacene film is formed on the 2D C60 structure, whereas an encapsulation of the 1D and 0D structures with uniformly upright oriented pentacene is achieved, hence allowing the fabrication of low dimensional buried organic heterostructures.

  20. Atkins' molecules

    CERN Document Server

    Atkins, Peters

    2003-01-01

    Originally published in 2003, this is the second edition of a title that was called 'the most beautiful chemistry book ever written'. In it, we see the molecules responsible for the experiences of our everyday life - including fabrics, drugs, plastics, explosives, detergents, fragrances, tastes, and sex. With engaging prose Peter Atkins gives a non-technical account of an incredible range of aspects of the world around us, showing unexpected connections, and giving an insight into how this amazing world can be understood in terms of the atoms and molecules from which it is built. The second edition includes dozens of extra molecules, graphical presentation, and an even more accessible and enthralling account of the molecules themselves.

  1. Interstellar Molecules

    Science.gov (United States)

    Solomon, Philip M.

    1973-01-01

    Radioastronomy reveals that clouds between the stars, once believed to consist of simple atoms, contain molecules as complex as seven atoms and may be the most massive objects in our Galaxy. (Author/DF)

  2. Extraction and high-performance liquid chromatographic analysis of C60, C70, and [6,6]-phenyl C61-butyric acid methyl ester in synthetic and natural waters.

    Science.gov (United States)

    Bouchard, Dermont; Ma, Xin

    2008-09-05

    Studies have shown that C(60) fullerene can form stable colloidal suspensions in water that result in C(60) aqueous concentrations many orders of magnitude above C(60)'s aqueous solubility; however, quantitative methods for the analysis of C(60) and other fullerenes in environmental media are scarce. Using a 80/20v/v toluene-acetonitrile mobile phase and a 4.6 mm x 150 mm Cosmosil 5micron PYE column, C(60), C(70), and PCBM ([6,6]-phenyl C(61)-butyric acid methyl ester) were fully resolved. Selectivity factors (alpha) for C(60) relative to PCBM and C(70) relative to C(60) were 3.18 and 2.19, respectively. The best analytical wavelengths for the fullerenes were determined to be 330, 333, and 333 nm with log molar absorption coefficients (log epsilon) of 4.63, 4.82, and 4.60 for PCBM, C(60), C(70), respectively. Extraction and quantitation of all three fullerenes in aqueous suspensions over a range of pH (4-10) and ionic strengths were very good. Whole-method quantification limits for ground and surface suspensions were 2.87, 2.48, and 6.54 microg/L for PCBM, C(60), and C(70), respectively.

  3. Entire solutions of Fermat type q-difference differential equations

    Directory of Open Access Journals (Sweden)

    Kai Liu

    2013-02-01

    Full Text Available In this article, we describe the finite-order transcendental entire solutions of Fermat type $q$-difference and $q$-difference differential equations. In addition, we investigate the similarities and other properties among those solutions.

  4. Single-Molecule Nanomagnets

    Science.gov (United States)

    Friedman, Jonathan R.; Sarachik, Myriam P.

    2010-04-01

    Single-molecule magnets straddle the classical and quantum mechanical worlds, displaying many fascinating phenomena. They may have important technological applications in information storage and quantum computation. We review the physical properties of two prototypical molecular nanomagnets, Mn12-acetate and Fe8: Each behaves as a rigid, spin-10 object and exhibits tunneling between up and down directions. As temperature is lowered, the spin-reversal process evolves from thermal activation to pure quantum tunneling. At low temperatures, magnetic avalanches occur in which the magnetization of an entire sample rapidly reverses. We discuss the important role that symmetry-breaking fields play in driving tunneling and in producing Berry-phase interference. Recent experimental advances indicate that quantum coherence can be maintained on timescales sufficient to allow a meaningful number of quantum computing operations to be performed. Efforts are under way to create monolayers and to address and manipulate individual molecules.

  5. Adhesion molecules

    CERN Document Server

    Preedy, Victor R

    2016-01-01

    This book covers the structure and classification of adhesion molecules in relation to signaling pathways and gene expression. It discusses immunohistochemical localization, neutrophil migration, and junctional, functional, and inflammatory adhesion molecules in pathologies such as leukocyte decompression sickness and ischemia reperfusion injury. Highlighting the medical applications of current research, chapters cover diabetes, obesity, and metabolic syndrome; hypoxia; kidney disease; smoking, atrial fibrillation, and heart disease, the brain and dementia; and tumor proliferation. Finally, it looks at molecular imaging and bioinformatics, high-throughput technologies, and chemotherapy.

  6. C20H4(C4F8)3: a fluorine-containing annulated corannulene that is a better electron acceptor than C60.

    Science.gov (United States)

    Kuvychko, Igor V; Dubceac, Cristina; Deng, Shihu H M; Wang, Xue-Bin; Granovsky, Alexander A; Popov, Alexey A; Petrukhina, Marina A; Strauss, Steven H; Boltalina, Olga V

    2013-07-15

    At sixes and sevens: The reaction of corannulene with 35 equivalents of 1,4-C4F8I2 is an efficient and a relatively selective process that yields two main products in which six H atoms are substituted with three C4F8 moieties that form six- and seven-membered rings. Low-temperature photoelectron spectroscopy showed the electron affinity of the major isomer (shown) exceeds that of C60 (2.74±0.02 and 2.689±0.008 eV, respectively). Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Thermal-induced changes on the properties of spin-coated P3HT:C60 thin films for solar cell applications

    CSIR Research Space (South Africa)

    Motaung, DE

    2009-09-01

    Full Text Available on the properties of spin- coated P3HT:C60 thin films for solar cell applications David E. Motaung1, 2, Gerald F. Malgas1,*, Christopher J. Arendse1, Sipho E. Mavundla1, 3 Clive J. Oliphant 1, 2 and Dirk Knoesen2 1National Centre for Nano...-structured Materials, Council for Scientific Industrial Research, P. O. Box 395, Pretoria, 0001, South Africa 2Deparment of Physics, University of the Western Cape, Private Bag X17, Bellville, 7535, South Africa 3Deparment of Chemistry, University of the Western...

  8. Modest vasomotor dysfunction induced by low doses of C60 fullerenes in apolipoprotein E knockout mice with different degree of atherosclerosis

    DEFF Research Database (Denmark)

    Vesterdal, Lise K; Folkmann, Janne K; Jacobsen, Nicklas R

    2009-01-01

    ABSTRACT: BACKGROUND: Exposure to small size particulate matter in urban air is regarded as a risk factor for cardiovascular effects, whereas there is little information about the impact on the cardiovascular system by exposure to pure carbonaceous materials in the nano-size range. C60 fullerenes...... (apoE-/-) with different degree of atherosclerosis. RESULTS: The aged apoE-/-mice had lower endothelium-dependent vasorelaxation elicited by acetylcholine in aorta segments mounted in myographs and the phenylephrine-dependent vasoconstriction response was increased. One hour after an intraperitoneal...

  9. Structural effects of C60+ bombardment on various natural mineral samples-Application to analysis of organic phases in geological samples

    International Nuclear Information System (INIS)

    Siljestroem, S.; Lausmaa, J.; Hode, T.; Sundin, M.; Sjoevall, P.

    2011-01-01

    Organic phases trapped inside natural mineral samples are of considerable interest in astrobiology, geochemistry and geobiology. Examples of such organic phases are microfossils, kerogen and oil. Information about these phases is usually retrieved through bulk crushing of the rock which means both a risk of contamination and that the composition and spatial distribution of the organics to its host mineral is lost. An attractive of way to retrieve information about the organics in the rock is depth profiling using a focused ion beam. Recently, it was shown that it is possible to obtain detailed mass spectrometric information from oil-bearing fluid inclusions, i.e. small amounts of oil trapped inside a mineral matrix, using ToF-SIMS. Using a 10 keV C 60 + sputter beam and a 25 keV Bi 3 + analysis beam, oil-bearing inclusions in different minerals were opened and analysed individually. However, sputtering with a C 60 + beam also induced other changes to the mineral surface, such as formation of topographic features and carbon deposition. In this paper, the cause of these changes is explored and the consequences of the sputter-induced features on the analysis of organic phases in natural mineral samples (quartz, calcite and fluorite) in general and fluid inclusions in particular are discussed. The dominating topographical features that were observed when a several micrometers deep crater is sputtered with 10 keV C 60 + ions on a natural mineral surface are conical-shaped and ridge-like structures that may rise several micrometers, pointing in the direction of the incident C 60 + ion beam, on an otherwise flat crater bottom. The sputter-induced structures were found to appear at places with different chemistry than the host mineral, including other minerals phases and fluid inclusions, while structural defects in the host material, such as polishing marks or scratches, did not necessarily result in sputter-induced structures. The ridge-like structures were often covered

  10. Linear-dendritic supramolecular complexes as nanoscale reaction vessels for "green" chemistry. Diels-Alder reactions between fullerene C60 and polycyclic aromatic hydrocarbons in aqueous medium.

    Science.gov (United States)

    Simonyan, Arsen; Gitsov, Ivan

    2008-10-21

    This study describes the first Diels-Alder (DA) reaction performed in aqueous medium with highly hydrophobic compounds-fullerene (C 60) as the dienophile and anthracene (An) or tetracene (Tet) as the dienes, respectively. The reactions are performed in nanocontainers, constructed by self-assembly of linear-dendritic amphiphilic copolymers with poly(ethylene glycol), PEG or poly(ethylene oxide), PEO as the hydrophilic blocks and poly(benzyl ether) monodendrons as the hydrophobic fragments: G3PEO13k, dG3 and dG2. Comparative studies under identical conditions are carried out with an amphiphilic linear-linear copolymer, poly(styrene)1800- block-PEO2100, PSt-PEO, and the nonionic surfactant Igepal CO-720, IP720. The binding affinity of supermolecules built of these amphiphiles toward the DA reagents decreases in the following order: G3PEO13k > dG3 > PSt-PEO > dG2 > IP720. The kinetic constant of binding is evaluated for tetracene and decreases in a similar fashion: 5 x 10 (-7) M/min (G3PEO13k), through 4 x 10 (-7) M/min (PSt-PEO) down to 1.5 x 10 (-7) M/min for IP720. The mobility of substrates encapsulated in the micellar core, estimated by pyrene fluorescence decay, is 95-121 ns for the micelles of the linear-dendritic copolymers and notably higher for PSt-PEO (152 ns), revealing the much denser interior of the linear analogue. The apparent kinetic constant for the DA reaction of C 60 and Tet within the G3PEO13k supermolecule in aqueous medium is markedly higher than in organic solvent (toluene), 208 vs 1.82 M /min. With G3PEO13k the conversions reach 49% for the DA reaction between C 60 and An, and 55% for C 60 and Tet. Besides the monoadduct (26.5% yield) the reaction with An produces exclusively increasing amounts of D 2 h -symmetric antipodal bis-adduct, whose yield reaches up to 22.5% after 48 h. In addition to the environmentally friendly conditions notable advantages of the synthetic strategy described are the extended stability of the linear

  11. Molecule Matters

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 16; Issue 12. Molecule Matters - Dinitrogen. A G Samuelson J Jabadurai. Volume 16 Issue 12 ... Author Affiliations. A G Samuelson1 J Jabadurai1. Department of Inroganic and Physical Chemistry, Indian Institute of Science, Bangalore 560 012, India.

  12. Molecule Matters

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 11; Issue 9. Molecule Matters - A Chromium Compound with a Quintuple Bond. K C Kumara Swamy. Feature Article Volume 11 Issue 9 September 2006 pp 72-75. Fulltext. Click here to view fulltext PDF. Permanent link:

  13. Asymmetric Flow Field Flow Fractionation of Aqueous C60 Nanoparticles with Size Determination by Dynamic Light Scattering and Quantification by Liquid Chromatography Atmospheric Pressure Photo-Ionization Mass Spectrometry

    Science.gov (United States)

    A size separation method was developed for aqueous C60 fullerene aggregates (aqu/C60) using asymmetric flow field flow fractionation (AF4) coupled to a dynamic light scattering detector in flow through mode. Surfactants, which are commonly used in AF4, were avoided as they may al...

  14. Pade approximants for entire functions with regularly decreasing Taylor coefficients

    International Nuclear Information System (INIS)

    Rusak, V N; Starovoitov, A P

    2002-01-01

    For a class of entire functions the asymptotic behaviour of the Hadamard determinants D n,m as 0≤m≤m(n)→∞ and n→∞ is described. This enables one to study the behaviour of parabolic sequences from Pade and Chebyshev tables for many individual entire functions. The central result of the paper is as follows: for some sequences {(n,m(n))} in certain classes of entire functions (with regular Taylor coefficients) the Pade approximants {π n,m(n) }, which provide the locally best possible rational approximations, converge to the given function uniformly on the compact set D={z:|z|≤1} with asymptotically best rate

  15. Entirely saturated unilateral smear of laser spot in CCD

    International Nuclear Information System (INIS)

    Zhang Zhen; Zhou Menglian; Zhang Jianmin; Lin Xinwei

    2013-01-01

    In the video of linear CCD camera being irradiated by 532 nm CW laser, the entirely saturated unilateral smear of laser spot was found. The smear area does not represent the distribution of laser. Since this smear lies merely in one side of laser spot, it can not be induced by light leaking or carriers blooming, and it may be induced by charge transfer loss. However, the feature that the smear area is entirely saturated can not be explained by the current constant model of charge transfer inefficiency. Based on the inner structure and operating principle of buried channel CCD, a new model of charge transfer inefficiency that varies with charge quantity is proposed, which can explain the entirely saturated unilateral smear of laser spot. (authors)

  16. Entirely irrelevant distractors can capture and captivate attention.

    Science.gov (United States)

    Forster, Sophie; Lavie, Nilli

    2011-12-01

    The question of whether a stimulus onset may capture attention when it is entirely irrelevant to the task and even in the absence of any attentional settings for abrupt onset or any dynamic changes has been highly controversial. In the present study, we designed a novel irrelevant capture task to address this question. Participants engaged in a continuous task making sequential forced choice (letter or digit) responses to each item in an alphanumeric matrix that remained on screen throughout many responses. This task therefore involved no attentional settings for onset or indeed any dynamic changes, yet the brief onset of an entirely irrelevant distractor (a cartoon picture) resulted in significant slowing of the two (Experiment 1) or three (Experiment 2) responses immediately following distractor appearance These findings provide a clear demonstration of attention being captured and captivated by a distractor that is entirely irrelevant to any attentional settings of the task.

  17. Selectable six-element multicoil array for entire spine imaging

    International Nuclear Information System (INIS)

    Byrne, J.W.; Bluma-Walter, J.; Prorok, R.J.

    1990-01-01

    This article introduces a new multicoil array that can provide entire spine imaging in two acquisitions with no need to manually reposition either the coil or the patient. A selectable contoured multicoil array with six elements was used to obtain coverage of the entire spine. The first four elements were used for imaging the upper spine region (cervical/thoracic) during the first acquisition, and the last four elements were used for imaging the lower spine region (thoracic/lumbar) during the second acquisition. The overall coil length was approximately 75 cm

  18. Robust Crosslinked Stereocomplexes and C60 Inclusion Complexes of Vinyl-Functionalized Stereoregular Polymers Derived from Chemo/Stereoselective Coordination Polymerization

    KAUST Repository

    Vidal, Fernando

    2016-07-07

    The successful synthesis of highly syndiotactic polar vinyl polymers bearing the reactive pendant vinyl group on each repeat unit, which is enabled by perfectly chemoselective and highly syndiospecific coordination polymerization of divinyl polar monomers developed through this work, has allowed the construction of robust crosslinked supramolecular stereocomplexes and C60 inclusion complexes. The metal-mediated coordination polymerization of three representative polar divinyl monomers, including vinyl methacrylate (VMA), allyl methacrylate (AMA), and N,N-diallyl acrylamide (DAA) by Cs-ligated zirconocenium ester enolate catalysts under ambient conditions exhibits complete chemoselectivity and high stereoselectivity, thus producing the corresponding vinyl-functionalized polymers with high (92% rr) to quantitative (>99% rr) syndiotacticity. A combined experimental (synthetic, kinetic, and mechanistic) and theoretical (DFT) investigation has yielded a unimetallic, enantiomorphic-site controlled propagation mechanism. Post-functionalization of the obtained syndiotactic vinyl-functionalized polymers via the thiol-ene click and photocuring reactions readily produced the corresponding thiolated polymers and flexible crosslinked thin film materials, respectively. Complexation of such syndiotactic vinyl-functionalized polymers with isotactic poly(methyl methacrylate) and fullerene C60 generates supramolecular crystalline helical stereocomplexes and inclusion complexes, respectively. Crosslinking of such complexes afforded robust crosslinked stereocomplexes that are solvent resistant and also exhibit considerably enhanced thermal and mechanical properties as compared to the uncrosslinked stereocompexes.

  19. Electronic structure, stability and non-linear optical properties of aza-fullerenes C60-2nN2n(n=1–12

    Directory of Open Access Journals (Sweden)

    K. Srinivasu

    2012-12-01

    Full Text Available Through ab initio based density functional theory calculations, we have investigated the electronic structure, stability and non-linear optical properties of a series of nitrogen substituted fullerenes (azafullerenes with the general formula C60-2nN2n (n=1–12. For each system, we have considered different possible isomers and the minimum energy isomer is subjected to further detailed investigations. We have calculated different properties such as HOMO-LUMO gaps, vertical ionization potentials, vertical electron affinities, etc. to verify the stability of the considered fullerenes. From the Hessian calculations, it is observed that all the fullerenes are not only associated with real vibrational frequencies, but the minimum frequencies are also found to be considerably large which further confirms the stability of the considered fullerenes. We find that the presence of unperturbed C6 rings enhances the stability of the fullerene whereas, the -N-C-N- fragments are found to destabilize the structure. At lower doping concentration, the stabilization due to C6 is more predominant and as the doping concentration is increased, the destabilization due to nitrogen-nitrogen repulsion plays a more important role. Our calculated polarizability and hyperpolarizability parameters of C60 are found to be in good agreement with the earlier reported results. On nitrogen doping, considerable variation is observed in the non-linear optical coefficients, which can be helpful in designing new photonic devices.

  20. Robust Crosslinked Stereocomplexes and C60 Inclusion Complexes of Vinyl-Functionalized Stereoregular Polymers Derived from Chemo/Stereoselective Coordination Polymerization

    KAUST Repository

    Vidal, Fernando; Falivene, Laura; Caporaso, Lucia; Cavallo, Luigi; Chen, Eugene Y.-X.

    2016-01-01

    The successful synthesis of highly syndiotactic polar vinyl polymers bearing the reactive pendant vinyl group on each repeat unit, which is enabled by perfectly chemoselective and highly syndiospecific coordination polymerization of divinyl polar monomers developed through this work, has allowed the construction of robust crosslinked supramolecular stereocomplexes and C60 inclusion complexes. The metal-mediated coordination polymerization of three representative polar divinyl monomers, including vinyl methacrylate (VMA), allyl methacrylate (AMA), and N,N-diallyl acrylamide (DAA) by Cs-ligated zirconocenium ester enolate catalysts under ambient conditions exhibits complete chemoselectivity and high stereoselectivity, thus producing the corresponding vinyl-functionalized polymers with high (92% rr) to quantitative (>99% rr) syndiotacticity. A combined experimental (synthetic, kinetic, and mechanistic) and theoretical (DFT) investigation has yielded a unimetallic, enantiomorphic-site controlled propagation mechanism. Post-functionalization of the obtained syndiotactic vinyl-functionalized polymers via the thiol-ene click and photocuring reactions readily produced the corresponding thiolated polymers and flexible crosslinked thin film materials, respectively. Complexation of such syndiotactic vinyl-functionalized polymers with isotactic poly(methyl methacrylate) and fullerene C60 generates supramolecular crystalline helical stereocomplexes and inclusion complexes, respectively. Crosslinking of such complexes afforded robust crosslinked stereocomplexes that are solvent resistant and also exhibit considerably enhanced thermal and mechanical properties as compared to the uncrosslinked stereocompexes.

  1. Teaching Discrete Mathematics Entirely from Primary Historical Sources

    Science.gov (United States)

    Barnett, Janet Heine; Bezhanishvili, Guram; Lodder, Jerry; Pengelley, David

    2016-01-01

    We describe teaching an introductory discrete mathematics course entirely from student projects based on primary historical sources. We present case studies of four projects that cover the content of a one-semester course, and mention various other courses that we have taught with primary source projects.

  2. Entire functions sharing one polynomial with their derivatives

    Indian Academy of Sciences (India)

    restriction of the hyper order less than 1/2, and obtain some uniqueness theorems of a nonconstant entire function and its derivative sharing a finite nonzero complex number. CM. The results in this paper also improve some known results. Some examples are provided to show that the results in this paper are best possible.

  3. Thermodynamics of Quantum Gases for the Entire Range of Temperature

    Science.gov (United States)

    Biswas, Shyamal; Jana, Debnarayan

    2012-01-01

    We have analytically explored the thermodynamics of free Bose and Fermi gases for the entire range of temperature, and have extended the same for harmonically trapped cases. We have obtained approximate chemical potentials for the quantum gases in closed forms of temperature so that the thermodynamic properties of the quantum gases become…

  4. Entire hemithorax irradiation for Masaoka stage IVa thymomas

    Science.gov (United States)

    Soares, André; Louro, Luís Vasco; Almeida, Marta; Sousa, Olga

    2012-01-01

    Thymomas are rare neoplasms that have an indolent growth with a preferentially intra-thoracic dissemination pattern. Surgery is currently the standard treatment of thymomas; however radiotherapy is often used in an adjuvant setting due to a high sensitivity of these tumors to such treatment. Postoperative entire hemithoracic irradiation has been used in selected Masaoka stage IVa cases after complete surgical excision of metastatic lesions. In the present article, the authors report three cases of Masaoka stage IVa thymoma that underwent entire hemithorax irradiation after surgical excision of metastatic lesions. The first two patients presented as stage IVa thymomas. The third case consisted of a pleural recurrence of a thymoma. Hemithoracic irradiation with low doses has been used by different authors; the available data shows that it is a well-tolerated treatment that could potentially lead to better loco-regional control and increased overall survival. PMID:24377042

  5. Multi-fragmentation of C60 induced by 4He2+ impact (E<60 keV/amu) and investigated by a multi-correlation technique

    International Nuclear Information System (INIS)

    Rentenier, A.; Moretto-Capelle, P.; Bordenave-Montesquieu, D.; Bordenave-Montesquieu, A.

    2003-01-01

    In this communication, the C 60 multi-fragmentation induced by 4 He 2+ ion impact in the 20-240 keV energy range, is investigated. Using a multi-stop time-of-flight technique, it becomes possible to measure partial spectra corresponding to the simultaneous emission of 2-5 light charged fragments; small charged fragments are found to be accompanied by the emission of at least another one. The fragment size distribution depends on the collisional energy and the multiplicity of emitted charged fragments. It is more peaked on small sizes when the collision velocity or the multiplicity increases. Corresponding relative cross sections are also measured; processes with emission of 2 and 3 charged fragments are always dominant but their relative weights decrease slowly when the collision energy increases

  6. Ultrafast electron transfer in all-carbon-based SWCNT-C60 donor-acceptor nanoensembles connected by poly(phenylene-ethynylene) spacers

    Science.gov (United States)

    Barrejón, Myriam; Gobeze, Habtom B.; Gómez-Escalonilla, María J.; Fierro, José Luis G.; Zhang, Minfang; Yudasaka, Masako; Iijima, Sumio; D'Souza, Francis; Langa, Fernando

    2016-08-01

    Building all-carbon based functional materials for light energy harvesting applications could be a solution to tackle and reduce environmental carbon output. However, development of such all-carbon based donor-acceptor hybrids and demonstration of photoinduced charge separation in such nanohybrids is a challenge since in these hybrids part of the carbon material should act as an electron donating or accepting photosensitizer while the second part should fulfil the role of an electron acceptor or donor. In the present work, we have successfully addressed this issue by synthesizing covalently linked all-carbon-based donor-acceptor nanoensembles using single-walled carbon nanotubes (SWCNTs) as the donor and C60 as the acceptor. The donor-acceptor entities in the nanoensembles were connected by phenylene-ethynylene spacer units to achieve better electronic communication and to vary the distance between the components. These novel SWCNT-C60 nanoensembles have been characterized by a number of techniques, including TGA, FT-IR, Raman, AFM, absorbance and electrochemical methods. The moderate number of fullerene addends present on the side-walls of the nanotubes largely preserved the electronic structure of the nanotubes. The thermodynamic feasibility of charge separation in these nanoensembles was established using spectral and electrochemical data. Finally, occurrence of ultrafast electron transfer from the excited nanotubes in these donor-acceptor nanohybrids has been established by femtosecond transient absorption studies, signifying their utility in building light energy harvesting devices.Building all-carbon based functional materials for light energy harvesting applications could be a solution to tackle and reduce environmental carbon output. However, development of such all-carbon based donor-acceptor hybrids and demonstration of photoinduced charge separation in such nanohybrids is a challenge since in these hybrids part of the carbon material should act as an

  7. Insight into doping efficiency of organic semiconductors from the analysis of the density of states in n-doped C60 and ZnPc

    Science.gov (United States)

    Gaul, Christopher; Hutsch, Sebastian; Schwarze, Martin; Schellhammer, Karl Sebastian; Bussolotti, Fabio; Kera, Satoshi; Cuniberti, Gianaurelio; Leo, Karl; Ortmann, Frank

    2018-05-01

    Doping plays a crucial role in semiconductor physics, with n-doping being controlled by the ionization energy of the impurity relative to the conduction band edge. In organic semiconductors, efficient doping is dominated by various effects that are currently not well understood. Here, we simulate and experimentally measure, with direct and inverse photoemission spectroscopy, the density of states and the Fermi level position of the prototypical materials C60 and zinc phthalocyanine n-doped with highly efficient benzimidazoline radicals (2-Cyc-DMBI). We study the role of doping-induced gap states, and, in particular, of the difference Δ1 between the electron affinity of the undoped material and the ionization potential of its doped counterpart. We show that this parameter is critical for the generation of free carriers and influences the conductivity of the doped films. Tuning of Δ1 may provide alternative strategies to optimize the electronic properties of organic semiconductors.

  8. Xe-129 NMR chemical shift in Xe@C-60 calculated at experimental conditions: Essential role of the relativity, dynamics, and explicit solvent

    Czech Academy of Sciences Publication Activity Database

    Standara, Stanislav; Kulhánek, P.; Marek, R.; Straka, Michal

    2013-01-01

    Roč. 34, č. 22 (2013), s. 1890-1898 ISSN 0192-8651 R&D Projects: GA ČR GA203/09/2037; GA ČR GA13-03978S Grant - others:7th European Community Framework Program(XE) FP7-286154; CEITEC-Central European Institute of Technology (European Regional Development)(XE) CZ.1.05/1.1.00/02.0068; Operational Program Research and Development for Innovations(XE) CZ.1.05/3.2.00/08.0144 Institutional support: RVO:61388963 Keywords : Xe-129 NMR * Xe@C-60 * dynamical averaging * explicit solvent * relativistic effects Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.601, year: 2013

  9. Entirely irrelevant distractors can capture and captivate attention

    OpenAIRE

    Forster, Sophie; Lavie, Nilli

    2011-01-01

    The question of whether a stimulus onset may capture attention when it is entirely irrelevant to the task and even in the absence of any attentional settings for abrupt onset or any dynamic changes has been highly controversial. In the present study, we designed a novel irrelevant capture task to address this question. Participants engaged in a continuous task making sequential forced choice (letter or digit) responses to each item in an alphanumeric matrix that remained on screen throughout ...

  10. Completely monotonic functions related to logarithmic derivatives of entire functions

    DEFF Research Database (Denmark)

    Pedersen, Henrik Laurberg

    2011-01-01

    The logarithmic derivative l(x) of an entire function of genus p and having only non-positive zeros is represented in terms of a Stieltjes function. As a consequence, (-1)p(xml(x))(m+p) is a completely monotonic function for all m ≥ 0. This generalizes earlier results on complete monotonicity...... of functions related to Euler's psi-function. Applications to Barnes' multiple gamma functions are given....

  11. C60 and Sc3N@C80(TMB-PPO derivatives as constituents of singlet oxygen generating, thiol-ene polymer nanocomposites

    Directory of Open Access Journals (Sweden)

    Ashli R. Toles

    2016-07-01

    Full Text Available Numerous functionalization methods have been employed to increase the solubility, and therefore, the processability of fullerenes in composite structures, and of these radical addition reactions continue to be an important methodology. C60 and Sc3N@C80 derivatives were prepared via radical addition of the photodecomposition products from the commercial photoinitiator TMB-PPO, yielding C60(TMB-PPO5 and Sc3N@C80(TMB-PPO3 as preferred soluble derivatives obtained in high yields. Characterization of the mixture of isomers using standard techniques suggests an overall 1PPO:6TMB ratio of addends, reflecting the increased reactivity of the carbon radical. Although, a higher percentage of PPO is observed in the Sc3N@C80(TMB-PPO3 population, perhaps due to reverse electronic requirements of the substrate. Visually dispersed thiol-ene nanocomposites with low extractables were prepared using two monomer compositions (PETMP:TTT and TMPMP:TMPDE with increasing fullerene derivative loading to probe network structure-property relationships. Thermal stability of the derivatives and the resulting networks decreased with increased functionality and at high fullerene loadings, respectively. TMPMP:TMPDE composite networks show well-dispersed derivatives via TEM imaging, and increasing Tg’s with fullerene loading, as expected for the incorporation of a more rigid network component. PETMP:TTT composites show phase separation in TEM, which is supported by the observed Tg’s. Singlet oxygen generation of the derivatives decreases with increased functionality; however, this is compensated for by the tremendous increase in solubility in organic solvents and miscibility with monomers. Most importantly, singlet oxygen generation from the composites increased with fullerene derivative loading, with good photostability of the networks.

  12. Nanometer-scale anatomy of entire Stardust tracks

    Science.gov (United States)

    Nakamura-Messenger, Keiko; Keller, Lindsay P.; Clemett, Simon J.; Messenger, Scott; Ito, Motoo

    2011-07-01

    We have developed new sample preparation and analytical techniques tailored for entire aerogel tracks of Wild 2 sample analyses both on "carrot" and "bulbous" tracks. We have successfully ultramicrotomed an entire track along its axis while preserving its original shape. This innovation allowed us to examine the distribution of fragments along the entire track from the entrance hole all the way to the terminal particle. The crystalline silicates we measured have Mg-rich compositions and O isotopic compositions in the range of meteoritic materials, implying that they originated in the inner solar system. The terminal particle of the carrot track is a 16O-rich forsteritic grain that may have formed in a similar environment as Ca-, Al-rich inclusions and amoeboid olivine aggregates in primitive carbonaceous chondrites. The track also contains submicron-sized diamond grains likely formed in the solar system. Complex aromatic hydrocarbons distributed along aerogel tracks and in terminal particles. These organics are likely cometary but affected by shock heating.

  13. A roentgenologic study of diverticular throughout the entire gastrointestinal tract

    International Nuclear Information System (INIS)

    Sohn, Myung Hee; Song, Ho Young; Lim, Kyu Yeob

    1983-01-01

    Diverticulum is considered as a common lesion involving any gastrointestinal tract from the pharynx to the rectum. We reviewed 5,806 cases of upper G-I series and 801 cases of double contrast barium enema during the period from Jan.1978 to Dec. 1981 in the Department of Radiology, School of Medicine, Jeonbug National University Hospital to analyze diverticula of the entire gastrointestinal tract. The results were as follows: 1. Roentgen examination of 5,806 esophagus, stomachs, duodenums and small bowels, and 801 colons during the past four years: diverticula of the esophagus, 60 cases (1.0%); diverticula of the stomach, 42 cases (0.7%); diverticula of the duodenum, 358 cases (6.2%); diverticula of the small bowel, 20 cases (0.3%); diverticula of the colon, 26 cases (3.2%). The location of diverticula in order of frequency was duodenum, colon, esophagus, stomach and small bowel. 2. The most common site of diverticula of each gastrointestinal tract was as follows: diverticula of the esophagus, middle portion (84.7%); diverticula of the stomach, the cardia (59.5%); diverticula of the duodenum, the second portion (81.3%); diverticula of the small bowel, the jejunum (96.4%)-especially the larger percentage were observed at the upper jejunum near the ligament of Treitz; diverticula of the colon, the right sided colon (80.8%)-the cecum and ascending colon (57.1%). 3. Diverticula may occur at any age. The majority of diverticula of the entire gastrointestinal tract were observed over 40 years of age. Especially in diverticula of the duodenum and colon, their frequency increase with age. 4. Duodenal diverticula were observed more frequently in woman than in man but in diverticula of the esophagus, stomach, small bowel and colon, male was more frequently affected. 5. The size of diverticula of the entire gastrointestinal tract was variable. The majority of diverticula of the esophagus, stomach, duodenum and small bowel were intermediate in size (10-49 mm). Diverticula of

  14. Molecule Matters van der Waals Molecules

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 12. Molecule Matters van der Waals Molecules - Noble Gas Clusters are London Molecules! E Arunan. Feature Article Volume 14 Issue 12 December 2009 pp 1210-1222 ...

  15. Implicit function with natural behavior over entire domain

    International Nuclear Information System (INIS)

    Itoh, Taku; Saitoh, Ayumu; Kamitani, Atsushi; Nakamura, Hiroaki

    2012-01-01

    To generate a smooth implicit function that behaves naturally over an entire domain, a method to smoothly combine an implicit function f(x) with a global support function g(x) has been proposed. The proposed method can be applied to large scattered point data, since the implicit function f(x) is generated by a partition-of-unity-based method. The global support function g(x) is generated by a radial basis function-based method or by the least-squares method. To ensure a smooth combination of f(x) and g(x), an appropriate weight function is employed. In numerical experiments, the proposed method is applied to large point data. The results illustrate that the proposed method can generate a smooth implicit function F(x) with natural behavior over the entire domain. In addition, on the given points, the accuracy of F(x) is exactly the same as that of f(x). Furthermore, the computational cost for generation of F(x) is almost the same as that of f(x). (author)

  16. No turnover in lens lipids for the entire human lifespan.

    Science.gov (United States)

    Hughes, Jessica R; Levchenko, Vladimir A; Blanksby, Stephen J; Mitchell, Todd W; Williams, Alan; Truscott, Roger J W

    2015-03-11

    Lipids are critical to cellular function and it is generally accepted that lipid turnover is rapid and dysregulation in turnover results in disease (Dawidowicz 1987; Phillips et al., 2009; Liu et al., 2013). In this study, we present an intriguing counter-example by demonstrating that in the center of the human ocular lens, there is no lipid turnover in fiber cells during the entire human lifespan. This discovery, combined with prior demonstration of pronounced changes in the lens lipid composition over a lifetime (Hughes et al., 2012), suggests that some lipid classes break down in the body over several decades, whereas others are stable. Such substantial changes in lens cell membranes may play a role in the genesis of age-related eye disorders. Whether long-lived lipids are present in other tissues is not yet known, but this may prove to be important in understanding the development of age-related diseases.

  17. Waste management aspects of entire PWR LOOP decontamination

    International Nuclear Information System (INIS)

    Murray, A.P.; Roesmer, J.

    1988-01-01

    The waste management parameters for decontamination of an entire PWR primary circuit have been determined for dilute alkaline-permanganate/citric acid (APCA), LOMI, ozone and cerium acid process variations. APCA processes generate the largest waste volumes; over 140 m 3 (5000 ft 3 ) in some cases. This represents a potential disposal cost of one million dollars. The cation regeneration column makes the greatest contribution to the disposal volume. In contrast, the LOMI process generates approximately half as much waste, but it is expected to contain relatively high metal concentrations (200-800 ppm). The ozone and cerium acid processes product the least waste, usually under 45 m 3 . These waste volume estimates represent considerable fractions of a utility's annual disposal volume. Consequently, improved waste processing technology is required, and several approaches are suggested

  18. Description of the Charge Transfer States at the Pentacene/C60 Interface: Combining Range-Separated Hybrid Functionals with the Polarizable Continuum Model

    KAUST Repository

    Zheng, Zilong

    2016-06-24

    Density functional theory (DFT) approaches based on range-separated hybrid functionals are currently methods of choice for the description of the charge-transfer (CT) states in organic donor/acceptor solar cells. However, these calculations are usually performed on small-size donor/acceptor complexes and as result do not account for electronic polarization effects. Here, using a pentacene/C60 complex as a model system, we discuss the ability of long-range corrected (LCR) hybrid functionals in combination with the polarizable continuum model (PCM) to determine the impact of the solid-state environment on the CT states. The CT energies are found to be insensitive to the interactions with the dielectric medium when a conventional time-dependent DFT/PCM (TDDFT/PCM) approach is used. However, a decrease in the energy of the CT state in the framework of LRC functionals can be obtained by using a smaller range-separated parameter when going from an isolated donor/acceptor complex to the solid-state case.

  19. The influence of the admixture of the fullerene C60 on the strength properties of aluminum and copper under shock-wave loading

    International Nuclear Information System (INIS)

    Bezruchko, G S; Razorenov, S V; Popov, M Y

    2014-01-01

    Hugoniot elastic limit (HEL) and dynamic (spall) strength measurements of pressed aluminum and copper samples with an admixture of the fullerene C60 with 2-5 wt% under shock-wave loading were carried out. The peak pressure in the shock-wave was equal to 6 GPa. The measurements of the elastic-plastic and strength properties were based on the recording and the subsequent analysis of the sample free surface velocity histories, recorded by Velocity Interferometric System for Any Reflection (VISAR). It was found that the admixture of 5 wt% fullerene in aluminum samples led to an increase of the Hugoniot elastic limit for aluminum samples by a factor of ten. The copper samples with the admixture of 2 wt% fullerene also demonstrated an increase of the Hugoniot elastic limit in comparison with commercial copper. The measured values of the Hugoniot elastic limit were equal to 0.82-1.56 GPa for aluminum samples and 1.35-3.46 GPa for copper samples, depending on their porosity. As expected, the spall strength of the samples with fullerene decreased by about three times in comparison with the undoped samples as a result of the influence of the solid fullerene particles which were concentrators of tension stresses in the material under dynamic fracture.

  20. Size Determination of Aqueous C60 by Asymmetric Flow Field-Flow Fractionation (AF4) and in-Line Dynamic Light Scattering

    Science.gov (United States)

    To date, studies on the environmental behaviour of aggregated aqueous fullerene nanomaterials have used the entire size distribution of fullerene aggregates and do not distinguish between different aggregate size classes. This is a direct result of the lack of analytical methods ...

  1. Satellite altimetry based rating curves throughout the entire Amazon basin

    Science.gov (United States)

    Paris, A.; Calmant, S.; Paiva, R. C.; Collischonn, W.; Silva, J. S.; Bonnet, M.; Seyler, F.

    2013-05-01

    The Amazonian basin is the largest hydrological basin all over the world. In the recent past years, the basin has experienced an unusual succession of extreme draughts and floods, which origin is still a matter of debate. Yet, the amount of data available is poor, both over time and space scales, due to factor like basin's size, access difficulty and so on. One of the major locks is to get discharge series distributed over the entire basin. Satellite altimetry can be used to improve our knowledge of the hydrological stream flow conditions in the basin, through rating curves. Rating curves are mathematical relationships between stage and discharge at a given place. The common way to determine the parameters of the relationship is to compute the non-linear regression between the discharge and stage series. In this study, the discharge data was obtained by simulation through the entire basin using the MGB-IPH model with TRMM Merge input rainfall data and assimilation of gage data, run from 1998 to 2010. The stage dataset is made of ~800 altimetry series at ENVISAT and JASON-2 virtual stations. Altimetry series span between 2002 and 2010. In the present work we present the benefits of using stochastic methods instead of probabilistic ones to determine a dataset of rating curve parameters which are consistent throughout the entire Amazon basin. The rating curve parameters have been computed using a parameter optimization technique based on Markov Chain Monte Carlo sampler and Bayesian inference scheme. This technique provides an estimate of the best parameters for the rating curve, but also their posterior probability distribution, allowing the determination of a credibility interval for the rating curve. Also is included in the rating curve determination the error over discharges estimates from the MGB-IPH model. These MGB-IPH errors come from either errors in the discharge derived from the gage readings or errors in the satellite rainfall estimates. The present

  2. Developing noise control strategies for entire railway networks

    Science.gov (United States)

    Oertli, Jakob

    2006-06-01

    The EU Environmental Noise Directive (2002/49) requires member states to deliver noise maps to the commission by 2007 and action plans by 2008 both for agglomerations as well as for major roads, railways and airports. Noise mitigation projects resulting from action plans are usually very expensive and therefore may threaten the economic viability of the railways in the current harsh competitive transport market, thus hindering sustainable transport policies. It is therefore of vital interest that the action plans and the resulting projects are designed in the most cost-effective way possible. The EU and Union of Railways (UIC) sponsored project Strategies and Tools to Assess and Implement noise Reducing measures for Railway Systems (STAIRRS) recognized this need and developed a tool, with which such optimal solutions can be obtained for entire railway networks. Since data collection is the most expensive part of the analysis, noise mapping data is ideally collected in such a way that it can be used for the calculation of the different scenarios, from which the most cost-effective action plans are chosen. The paper shows how the STAIRRS tool is used for this purpose and how cost-effectiveness considerations have led to optimal railway noise mitigation strategies in Switzerland and have given a basis for noise related decision making in Luxembourg.

  3. Use of the entire spectrum of irradiated alanine for dosimetry

    International Nuclear Information System (INIS)

    Dolo, J.M.; Moignau, F.

    2005-01-01

    Alanine is an amino acid commonly used in ESR dosimetry as a reference detector. The classic approach for the measurement of irradiated samples is to determine the amplitude of the central peak of the first derivative spectrum. It is generally considered that this technique represents the best and most reproducible solution for achieving an accurate proportionality between the concentration of free radicals inside the resonant cavity, characterized by the amplitude, and the dose. It is also accepted that this central peak corresponds to the free radical CH 3 .CHCOO - . The hyperfine structure of this radical in the spectrum shows five main peaks with the approximate ratios 1:4:6:4:1 as regards coupling. This paper presents another approach featuring analysis of the entire spectrum: (i) ratios of identified peaks (ii) ratio variation vs time with regard to several parameters affecting fading. These variations in the alanine spectrum are probably correlated with the variation of the concentrations of different free radical species. These variations and their positions in the spectrum are very important constraints that increase the uncertainty of this type of measurement

  4. Intrahippocampal Pathways Involved in Learning/Memory Mechanisms are Affected by Intracerebral Infusions of Amyloid-β25-35 Peptide and Hydrated Fullerene C60 in Rats.

    Science.gov (United States)

    Gordon, Rita; Podolski, Igor; Makarova, Ekaterina; Deev, Alexander; Mugantseva, Ekaterina; Khutsyan, Sergey; Sengpiel, Frank; Murashev, Arkady; Vorobyov, Vasily

    2017-01-01

    Primary memory impairments associated with increased level of amyloid-β (Aβ) in the brain have been shown to be linked, partially, with early pathological changes in the entorhinal cortex (EC) which spread on the whole limbic system. While the hippocampus is known to play a key role in learning and memory mechanisms, it is as yet unclear how its structures are involved in the EC pathology. In this study, changes in memory and neuronal morphology in male Wistar rats intrahippocampally injected with Aβ25-35 were correlated on days 14 and 45 after the injection to reveal specific cognitive-structural associations. The main focus was on the dentate gyrus (DG) and hippocampal areas of CA1 and CA3 because of their involvement in afferent flows from EC to the hippocampus through tri-synaptic (EC → DG → CA3 → CA1) and/or mono-synaptic (EC → CA1) pathways. Evident memory impairments were observed at both time points after Aβ25-35 injection. However, on day 14, populations of morphological intact neurons were decreased in CA3 and, drastically, in CA1, and the DG supramedial bundle was significantly damaged. On day 45, this bundle largely and CA1 neurons partially recovered, whereas CA3 neurons remained damaged. We suggest that Aβ25-35 primarily affects the tri-synaptic pathway, destroying the granular cells in the DG supramedial area and neurons in CA3 and, through the Schaffer collaterals, in CA1. Intrahippocampal pretreatment with hydrated fullerene C60 allows the neurons and their connections to survive the amyloidosis, thus supporting the memory mechanisms.

  5. Kinematics of the entire East African Rift from GPS velocities

    Science.gov (United States)

    Floyd, M.; King, R. W.

    2017-12-01

    Through a collaborative effort of the GeoPRISMS East Africa Rift GPS Working Group, we have collected and collated all of the publicly available continuous and survey-mode data for the entire rift system between 1994 and 2017 and processed these data as part of a larger velocity solution for Africa, Arabia and western Eurasia. We present here our velocity solution encompassing the major bounding plates and intervening terranes along the East African Rift from the Red Sea to the Malawi Rift and adjacent regions for GPS sites with data spans of at least 2.4 years, and north and east velocity uncertainties less than 1.5 mm/yr. To obtain realistic uncertainties for the velocity estimates, we attempted at each stage of the analysis to account for the character of the noise: During phase processing, we used an elevation-dependent weighting based on the phase residuals for each station; we then examined each position time series, removing outliers and reweighting appropriately to account for the white noise component of the errors; and e accounted for temporal correlations by estimating an equivalent random-walk magnitude for each continuous site and applying the median value (0.5 mm/√yr) to all survey-mode sites. We rigorously estimate relative rotation rates of Nubia, by choosing subset of well-determined sites such that the effective weights of western, northeastern and southern Africa were roughly equivalent, and Somalia, for which the estimate is dominated by three sites (MALI, RCMN, SEY1) whose uncertainties are a factor of 2-3 smaller than those of the other sites. For both plates, the weighted root-mean-square of the velocity residuals is 0.5 mm/yr. Our unified velocity solution provides a geodetic framework and constraints on the continental-scale kinematics of surface motions as well as more local effects both within and outside of the rift structures. Specific focus areas with denser coverage than previous fields include the Danakil block, the Afar Rift, the

  6. Molecule Matters van der Waals Molecules

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 7. Molecule Matters van der Waals Molecules - Rg•••HF Complexes are Debye Molecules! E Arunan. Feature Article Volume 15 Issue 7 July 2010 pp 667-674. Fulltext. Click here to view fulltext PDF. Permanent link:

  7. Water and oxygen induced degradation of small molecule organic solar cells

    DEFF Research Database (Denmark)

    Hermenau, Martin; Riede, Moritz; Leo, Karl

    2011-01-01

    Small molecule organic solar cells were studied with respect to water and oxygen induced degradation by mapping the spatial distribution of reaction products in order to elucidate the degradation patterns and failure mechanisms. The active layers consist of a 30 nm bulk heterojunction formed......,4′-diamine p-doped with C60F36 (MeO-TPD:C60F36), which acted as hole transporting layer. Indium-tin-oxide (ITO) and aluminum served as hole and electron collecting electrode, respectively. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS) in conjunction...... of aluminum oxide at the BPhen/Al interface, and diffusion of water into the ZnPc:C60 layer where ZnPc becomes oxidized. Finally, diffusion from the electrodes was found to have no or a negligible effect on the device lifetime....

  8. Kohn-Sham potentials for fullerenes and spherical molecules

    International Nuclear Information System (INIS)

    Pavlyukh, Y.; Berakdar, J.

    2010-01-01

    We present a procedure for the construction of accurate Kohn-Sham potentials of quasispherical molecules starting from the first-principles valence densities. The method is demonstrated for the case of icosahedral C 20 2+ and C 60 molecules. Provided the density is N representable the Hohenberg-Kohn theorem guarantees the uniqueness of the obtained potentials. The potential is iteratively built following the suggestion of R. van Leeuwen and E. J. Baerends [Phys. Rev. A 49, 2421 (1994)]. The high symmetry of the molecules allows a parametrization of the angular dependence of the densities and the potentials using a small number of symmetry-adapted spherical harmonics. The radial behavior of these quantities is represented on a grid and the density is reconstructed from the approximate potential by numerically solving the coupled-channel Kohn-Sham equations. Subsequently, the potential is updated and the procedure is continued until convergence is achieved.

  9. Conductance of single atoms and molecules studied with a scanning tunnelling microscope

    International Nuclear Information System (INIS)

    Neel, N; Kroeger, J; Limot, L; Berndt, R

    2007-01-01

    The conductance of single atoms and molecules is investigated with a low-temperature scanning tunnelling microscope. In a controlled and reproducible way, clean Ag(111) surfaces, individual silver atoms on Ag(111) as well as individual C 60 molecules adsorbed on Cu(100) are contacted with the tip of the microscope. Upon contact the conductance changes discontinuously in the case of the tip-surface junction while the tip-atom and tip-molecule junctions exhibit a continuous transition from the tunnelling to the contact regime

  10. Formation of Ultracold Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Cote, Robin [Univ. of Connecticut, Storrs, CT (United States)

    2016-01-28

    Advances in our ability to slow down and cool atoms and molecules to ultracold temperatures have paved the way to a revolution in basic research on molecules. Ultracold molecules are sensitive of very weak interactions, even when separated by large distances, which allow studies of the effect of those interactions on the behavior of molecules. In this program, we have explored ways to form ultracold molecules starting from pairs of atoms that have already reached the ultracold regime. We devised methods that enhance the efficiency of ultracold molecule production, for example by tuning external magnetic fields and using appropriate laser excitations. We also investigates the properties of those ultracold molecules, especially their de-excitation into stable molecules. We studied the possibility of creating new classes of ultra-long range molecules, named macrodimers, thousand times more extended than regular molecules. Again, such objects are possible because ultra low temperatures prevent their breakup by collision. Finally, we carried out calculations on how chemical reactions are affected and modified at ultracold temperatures. Normally, reactions become less effective as the temperature decreases, but at ultracold temperatures, they can become very effective. We studied this counter-intuitive behavior for benchmark chemical reactions involving molecular hydrogen.

  11. The status of molecules

    International Nuclear Information System (INIS)

    Barnes, T.; Oak Ridge National Lab., TN; Tennessee Univ., Knoxville, TN

    1994-06-01

    This report summarizes the experimental and theoretical status of hadronic molecules, which are weakly-bound states of two or more hadrons. We begin with a brief history of the subject and discuss a few good candidates, and then abstract some signatures for molecules which may be of interest in the classification of possible molecule states. Next we argue that a more general understanding of 2 → 2 hadron-hadron scattering amplitudes will be crucial for molecule searches, and discuss some of our recent work in this area. We conclude with a discussion of a few more recent molecule candidates (notably the f o (1710)) which are not well established as molecules but satisfy some of the expected signatures. (Author)

  12. On the growth estimates of entire functions of double complex variables

    Directory of Open Access Journals (Sweden)

    Sanjib Datta

    2017-08-01

    Full Text Available Recently Datta et al. (2016 introduced the idea of relative type and relative weak type of entire functions of two complex variables with respect to another entire function of two complex variables and prove some related growth properties of it. In this paper, further we study some growth properties of entire functions of two complex variables on the basis of their relative types and relative weak types as introduced by Datta et al (2016.

  13. Synthesis of single-molecule nanocars.

    Science.gov (United States)

    Vives, Guillaume; Tour, James M

    2009-03-17

    The drive to miniaturize devices has led to a variety of molecular machines inspired by macroscopic counterparts such as molecular motors, switches, shuttles, turnstiles, barrows, elevators, and nanovehicles. Such nanomachines are designed for controlled mechanical motion and the transport of nanocargo. As researchers miniaturize devices, they can consider two complementary approaches: (1) the "top-down" approach, which reduces the size of macroscopic objects to reach an equivalent microscopic entity using photolithography and related techniques and (2) the "bottom-up" approach, which builds functional microscopic or nanoscopic entities from molecular building blocks. The top-down approach, extensively used by the semiconductor industry, is nearing its scaling limits. On the other hand, the bottom-up approach takes advantage of the self-assembly of smaller molecules into larger networks by exploiting typically weak molecular interactions. But self-assembly alone will not permit complex assembly. Using nanomachines, we hope to eventually consider complex, enzyme-like directed assembly. With that ultimate goal, we are currently exploring the control of nanomachines that would provide a basis for the future bottom-up construction of complex systems. This Account describes the synthesis of a class of molecular machines that resemble macroscopic vehicles. We designed these so-called nanocars for study at the single-molecule level by scanning probe microscopy (SPM). The vehicles have a chassis connected to wheel-terminated axles and convert energy inputs such as heat, electric fields, or light into controlled motion on a surface, ultimately leading to transport of nanocargo. At first, we used C(60) fullerenes as wheels, which allowed the demonstration of a directional rolling mechanism of a nanocar on a gold surface by STM. However, because of the low solubility of the fullerene nanocars and the incompatibility of fullerenes with photochemical processes, we developed new

  14. Fluctuation in Interface and Electronic Structure of Single-Molecule Junctions Investigated by Current versus Bias Voltage Characteristics.

    Science.gov (United States)

    Isshiki, Yuji; Fujii, Shintaro; Nishino, Tomoaki; Kiguchi, Manabu

    2018-03-14

    Structural and electronic detail at the metal-molecule interface has a significant impact on the charge transport across the molecular junctions, but its precise understanding and control still remain elusive. On the single-molecule scale, the metal-molecule interface structures and relevant charge transport properties are subject to fluctuation, which contain the fundamental science of single-molecule transport and implication for manipulability of the transport properties in electronic devices. Here, we present a comprehensive approach to investigate the fluctuation in the metal-molecule interface in single-molecule junctions, based on current-voltage ( I- V) measurements in combination with first-principles simulation. Contrary to conventional molecular conductance studies, this I- V approach provides a correlated statistical description of both the degree of electronic coupling across the metal-molecule interface and the molecular orbital energy level. This statistical approach was employed to study fluctuation in single-molecule junctions of 1,4-butanediamine (DAB), pyrazine (PY), 4,4'-bipyridine (BPY), and fullerene (C 60 ). We demonstrate that molecular-dependent fluctuation of σ-, π-, and π-plane-type interfaces can be captured by analyzing the molecular orbital (MO) energy level under mechanical perturbation. While the MO level of DAB with the σ-type interface shows weak distance dependence and fluctuation, the MO level of PY, BPY, and C 60 features unique distance dependence and molecular-dependent fluctuation against the mechanical perturbation. The MO level of PY and BPY with the σ+π-type interface increases with the increase in the stretch distance. In contrast, the MO level of C 60 with the π-plane-type interface decreases with the increase in the stretching perturbation. This study provides an approach to resolve the structural and electronic fluctuation in the single-molecule junctions and insight into the molecular-dependent fluctuation in

  15. Cold Rydberg molecules

    Science.gov (United States)

    Raithel, Georg; Zhao, Jianming

    2017-04-01

    Cold atomic systems have opened new frontiers at the interface of atomic and molecular physics. These include research on novel types of Rydberg molecules. Three types of molecules will be reviewed. Long-range, homonuclear Rydberg molecules, first predicted in [1] and observed in [2], are formed via low-energy electron scattering of the Rydberg electron from a ground-state atom within the Rydberg atom's volume. The binding mostly arises from S- and P-wave triplet scattering. We use a Fermi model that includes S-wave and P-wave singlet and triplet scattering, the fine structure coupling of the Rydberg atom and the hyperfine structure coupling of the 5S1/2 atom (in rubidium [3]). The hyperfine structure gives rise to mixed singlet-triplet potentials for both low-L and high-L Rydberg molecules [3]. A classification into Hund's cases [3, 4, 5] will be discussed. The talk further includes results on adiabatic potentials and adiabatic states of Rydberg-Rydberg molecules in Rb and Cs. These molecules, which have even larger bonding length than Rydberg-ground molecules, are formed via electrostatic multipole interactions. The leading interaction term of neutral Rydberg-Rydberg molecules is between two dipoles, while for ionic Rydberg molecules it is between a dipole and a monopole. NSF (PHY-1506093), NNSF of China (61475123).

  16. Molecule of the Month

    Indian Academy of Sciences (India)

    Atoms in a molecule generally prefer, particularly among the neighbouring ones, certain optimmn geometrical relationships. These are manifested in specific ranges of bond lengths, bond angles, torsion angles etc. As it always happens, chemists are interested in making molecules where these 'standard relationships' are ...

  17. Molecule of the Month

    Indian Academy of Sciences (India)

    Cyclo bu tadiene (1) has been one of the most popular molecules for experimentalists and theoreticians. This molecule is unstable as . it is antiaromatic ( 4,n electrons in a cyclic array). Even though some highly substituted cyclobutadienes, for example, compound 2 and the Fe(CO)3 complex of cyclobutadiene (3) are ...

  18. Single-Molecule Spectroscopy

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 2. Single-Molecule Spectroscopy: Every Molecule is Different! Kankan Bhattacharyya. General Article Volume 20 Issue 2 February 2015 pp 151-164. Fulltext. Click here to view fulltext PDF. Permanent link:

  19. Single molecule conductance

    NARCIS (Netherlands)

    Willems, R.

    2008-01-01

    This thesis represents an excursion into the world of molecular electronics, i.e. the field of research trying to use individual (organic) molecules as electronic components; in this work various experimental methods have been explored to connect individual molecules to metallic contacts and

  20. Effect of faecal soiling on skatole and androstenone occurrence in organic entire male pigs

    DEFF Research Database (Denmark)

    Thomsen, Rikke; Edwards, Sandra; Jensen, Bent Borg

    2015-01-01

    Production of entire male pigs could be a future strategy for organic pig production. However, production of entire males leads to increased risk of carcasses with elevated boar taint levels. It is hypothesized that skatole levels in pig meat are affected by faecal soiling and that organic housing...

  1. Molecules in stars

    International Nuclear Information System (INIS)

    Tsuji, T.

    1986-01-01

    Recently, research related to molecules in stars has rapidly expanded because of progress in related fields. For this reason, it is almost impossible to cover all the topics related to molecules in stars. Thus, here the authors focus their attention on molecules in the atmospheres of cool stars and do not cover in any detail topics related to circumstellar molecules originating from expanding envelopes located far from the stellar surface. However, the authors do discuss molecules in quasi-static circumstellar envelopes (a recently discovered new component of circumstellar envelopes) located near the stellar surface, since molecular lines originating from such envelopes show little velocity shift relative to photospheric lines, and hence they directly affect the interpretation and analysis of stellar spectra

  2. Collective electronic excitations in C60 crystals

    International Nuclear Information System (INIS)

    Wu, X.; Ulloa, S.E.

    1994-01-01

    We present a theoretical study of the electronic excitations in fullerene crystals by calculating the density-density correlation function in a fully nonlocal linear response theory. Our results indicate that the collective features associates with the π→π * transitions show strong anisotropic properties, with peaks changing by as much as 0.7 eV in different directions. Meanwhile, the calculated mode dispersion exhibits rather weak wave-number dependence along a given direction, in general agreement with experimental results. The oscillator strength also shows anisotropic behavior, with significant weight redistribution for different directions. We also analyze this system in terms of a classical point-dipole array model, and show that this simple model approximates well the quantum results

  3. Dynamics of Activated Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Mullin, Amy S. [Univ. of Maryland, College Park, MD (United States)

    2016-11-16

    Experimental studies have been performed to investigate the collisional energy transfer processes of gas-phase molecules that contain large amounts of internal energy. Such molecules are prototypes for molecules under high temperature conditions relevant in combustion and information about their energy transfer mechanisms is needed for a detailed understanding and modeling of the chemistry. We use high resolution transient IR absorption spectroscopy to measure the full, nascent product distributions for collisions of small bath molecules that relax highly vibrationally excited pyrazine molecules with E=38000 cm-1 of vibrational energy. To perform these studies, we developed new instrumentation based on modern IR light sources to expand our experimental capabilities to investigate new molecules as collision partners. This final report describes our research in four areas: the characterization of a new transient absorption spectrometer and the results of state-resolved collision studies of pyrazine(E) with HCl, methane and ammonia. Through this research we have gained fundamental new insights into the microscopic details of relatively large complex molecules at high energy as they undergo quenching collisions and redistribute their energy.

  4. Dissociation in small molecules

    International Nuclear Information System (INIS)

    Dehmer, P.M.

    1982-01-01

    The study of molecular dissociation processes is one of the most interesting areas of modern spectroscopy owing to the challenges presented bt even the simplest of diatomic molecules. This paper reviews the commonly used descriptions of molecular dissociation processes for diatomic molecules, the selection rules for predissociation, and a few of the principles to be remembered when one is forced to speculate about dissociation mechanisms in a new molecule. Some of these points will be illustrated by the example of dissociative ionization in O 2

  5. Monte Carlo simulation of efficient data acquisition for an entire-body PET scanner

    Energy Technology Data Exchange (ETDEWEB)

    Isnaini, Ismet; Obi, Takashi [Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503 (Japan); Yoshida, Eiji, E-mail: rush@nirs.go.jp [National Institute of Radiological Sciences, 4-9-1 Inage-ku, Chiba 263-8555 (Japan); Yamaya, Taiga [National Institute of Radiological Sciences, 4-9-1 Inage-ku, Chiba 263-8555 (Japan)

    2014-07-01

    Conventional PET scanners can image the whole body using many bed positions. On the other hand, an entire-body PET scanner with an extended axial FOV, which can trace whole-body uptake images at the same time and improve sensitivity dynamically, has been desired. The entire-body PET scanner would have to process a large amount of data effectively. As a result, the entire-body PET scanner has high dead time at a multiplex detector grouping process. Also, the entire-body PET scanner has many oblique line-of-responses. In this work, we study an efficient data acquisition for the entire-body PET scanner using the Monte Carlo simulation. The simulated entire-body PET scanner based on depth-of-interaction detectors has a 2016-mm axial field-of-view (FOV) and an 80-cm ring diameter. Since the entire-body PET scanner has higher single data loss than a conventional PET scanner at grouping circuits, the NECR of the entire-body PET scanner decreases. But, single data loss is mitigated by separating the axially arranged detector into multiple parts. Our choice of 3 groups of axially-arranged detectors has shown to increase the peak NECR by 41%. An appropriate choice of maximum ring difference (MRD) will also maintain the same high performance of sensitivity and high peak NECR while at the same time reduces the data size. The extremely-oblique line of response for large axial FOV does not contribute much to the performance of the scanner. The total sensitivity with full MRD increased only 15% than that with about half MRD. The peak NECR was saturated at about half MRD. The entire-body PET scanner promises to provide a large axial FOV and to have sufficient performance values without using the full data.

  6. A dual-type responsive electrochemical immunosensor for quantitative detection of PCSK9 based on n-C60-PdPt/N-GNRs and Pt-poly (methylene blue) nanocomposites.

    Science.gov (United States)

    Li, Yan; He, Junlin; Chen, Jun; Niu, Yazhen; Zhao, Yilin; Zhang, Yuchan; Yu, Chao

    2018-03-15

    In this study, a dual-type responsive electrochemical immunosensor was developed for the quantitative detection of proprotein convertase subtilisin/kexin type 9 (PCSK9), a potential biomarker of cardiovascular disease in serum. N-doped graphene nanoribbons (N-GNRs) with good conductivity were used as the sensing matrix modifying the glassy carbon electrode. Palladium platinum alloy (PdPt) nanoparticles with high catalytic performance toward the reduction of hydrogen peroxide (H 2 O 2 ) were reduced onto amino-functionalized fullerene (n-C 60 -PdPt) and significantly amplified the electrochemical signal recorded by the amperometric i-t curve. Furthermore, staphylococcus protein A (SPA) with antibody orientation function was introduced to improve the immunoreaction efficiency. Accordingly, a label-free immunosensor was fabricated based on n-C 60 -PdPt/N-GNRs for the quick detection of PCSK9. Meanwhile, to realize ultrasensitive detection of PCSK9, Pt-poly (methylene blue) (Pt-PMB) nanocomposites synthesized by a one-pot method for the first time were used as a novel signal label, which exhibited uniform morphology as well as good conductivity and produced an electrochemical signal recorded by differential pulse voltammetry (DPV). Herein, a novel sandwich-type immunosensor was designed using n-C 60 -PdPt/N-GNRs as the sensing matrix and Pt-PMB as the signal label for sensitive detection of PCSK9. Under optimal conditions, the label-free immunosensor showed a linear range of 10pgmL -1 to 100ngmL -1 with a detection limit of 3.33pgmL -1 (S/N=3), and the sandwich-type immunosensor exhibited a linear range of 100 fg mL -1 to 100ngmL -1 with a detection limit of 0.033pgmL -1 (S/N=3) for PCSK9 detection, indicating its potential application in clinical bioassay analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Entire Functions of Bounded L-Index: Its Zeros and Behavior of Partial Logarithmic Derivatives

    Directory of Open Access Journals (Sweden)

    Andriy Bandura

    2017-01-01

    Full Text Available In this paper, we obtain new sufficient conditions of boundedness of L-index in joint variables for entire function in Cn functions. They give an estimate of maximum modulus of an entire function by its minimum modulus on a skeleton in a polydisc and describe the behavior of all partial logarithmic derivatives and the distribution of zeros. In some sense, the obtained results are new for entire functions of bounded index and l-index in C too. They generalize known results of Fricke, Sheremeta, and Kuzyk.

  8. Entire solutions of a diffusive and competitive Lotka–Volterra type system with nonlocal delays

    International Nuclear Information System (INIS)

    Wang, Mingxin; Lv, Guangying

    2010-01-01

    This paper is concerned with the entire solution of a diffusive and competitive Lotka–Volterra type system with nonlocal delays. The existence of the entire solution is proved by transforming the system with nonlocal delays to a four-dimensional system without delay and using the comparing argument and the sub-super-solution method. Here an entire solution means a classical solution defined for all space and time variables, which behaves as two wave fronts coming from both sides of the x-axis

  9. Desorption of large molecules with light-element clusters: Effects of cluster size and substrate nature

    International Nuclear Information System (INIS)

    Delcorte, Arnaud; Garrison, Barbara J.

    2011-01-01

    This contribution focuses on the conditions required to desorb a large hydrocarbon molecule using light-element clusters. The test molecule is a 7.5 kDa coil of polystyrene (PS61). Several projectiles are compared, from C 60 to 110 kDa organic droplets and two substrates are used, amorphous polyethylene and mono-crystalline gold. Different aiming points and incidence angles are examined. Under specific conditions, 10 keV nanodrops can desorb PS61 intact from a gold substrate and from a soft polyethylene substrate. The prevalent mechanism for the desorption of intact and 'cold' molecules is one in which the molecules are washed away by the projectile constituents and entrained in their flux, with an emission angle close to ∼70 deg. The effects of the different parameters on the dynamics and the underlying physics are discussed in detail and the predictions of the model are compared with other published studies.

  10. Single molecules and nanotechnology

    CERN Document Server

    Vogel, Horst

    2007-01-01

    This book focuses on recent advances in the rapidly evolving field of single molecule research. These advances are of importance for the investigation of biopolymers and cellular biochemical reactions, and are essential to the development of quantitative biology. Written by leading experts in the field, the articles cover a broad range of topics, including: quantum photonics of organic dyes and inorganic nanoparticles their use in detecting properties of single molecules the monitoring of single molecule (enzymatic) reactions single protein (un)folding in nanometer-sized confined volumes the dynamics of molecular interactions in biological cells The book is written for advanced students and scientists who wish to survey the concepts, techniques and results of single molecule research and assess them for their own scientific activities.

  11. Electron-molecule collisions

    CERN Document Server

    Takayanagi, Kazuo

    1984-01-01

    Scattering phenomena play an important role in modern physics. Many significant discoveries have been made through collision experiments. Amongst diverse kinds of collision systems, this book sheds light on the collision of an electron with a molecule. The electron-molecule collision provides a basic scattering problem. It is scattering by a nonspherical, multicentered composite particle with its centers having degrees of freedom of motion. The molecule can even disintegrate, Le., dissociate or ionize into fragments, some or all of which may also be molecules. Although it is a difficult problem, the recent theoretical, experimental, and computational progress has been so significant as to warrant publication of a book that specializes in this field. The progress owes partly to technical develop­ ments in measurements and computations. No less important has been the great and continuing stimulus from such fields of application as astrophysics, the physics of the earth's upper atmosphere, laser physics, radiat...

  12. Molecules to Materials

    Indian Academy of Sciences (India)

    evolved as a new line of thinking wherein a single molecule or perhaps a collection .... In photonic communication processes, laser light has to be modulated and .... The author wishes to thank G Rajaram for a critical reading of the manuscript.

  13. Single-Molecule Spectroscopy

    Indian Academy of Sciences (India)

    IAS Admin

    overall absorption spectrum of a molecule is a superposition of many such sharp lines .... dilute solution of the enzyme and the substrate over few drops of silicone oil placed ..... Near-field Scanning Optical Microscopy (NSOM): Development.

  14. Quantum dot molecules

    CERN Document Server

    Wu, Jiang

    2014-01-01

    This book reviews recent advances in the exciting and rapidly growing field of quantum dot molecules (QDMs). It offers state-of-the-art coverage of novel techniques and connects fundamental physical properties with device design.

  15. Molecule of the Month

    Indian Academy of Sciences (India)

    Molecule of the Month - Adamantane - A Plastic Piece of Diamond. J Chandrasekhar. Volume 16 Issue 12 ... Keywords. Adamantane; diamondoid systems; plastic crystals. ... Resonance – Journal of Science Education | News. © 2017 Indian ...

  16. Effect of substrate temperature on orientation of subphthalocyanine molecule in organic photovoltaic cells

    International Nuclear Information System (INIS)

    Chou, Chi-Ta; Tang, Wei-Li; Tai, Yian; Lin, Chien-Hung; Liu, Chin-Hsin J.; Chen, Li-Chyong; Chen, Kuei-Hsien

    2012-01-01

    This study investigates the effect of substrate temperature (T s ) on the boron subphthalocyanine chloride (SubPc) thin film and its power conversion efficiency in SubPc/C 60 heterojunction photovoltaic cells. The orientations of SubPc molecules in thin films determined by X-ray diffraction is strongly correlated with the electronic properties of the organic thin films, and can be controlled by the substrate temperature during the vapor deposition. An optimal substrate temperature of 120 °C has been concluded to induced (221) molecular orientation over the (122) orientation and significantly improve the carrier transport of the SubPc thin film. A SubPc/C 60 heterojunction photovoltaic cells thus fabricated shows higher open-circuit voltage and up to 1.55% conversion efficiency has been achieved, which is attributed to preferential (221) orientation of the SubPc deposited at the elevated temperature.

  17. Asymptotic behavior of the logarithmic derivative for entire functions of order zero

    Directory of Open Access Journals (Sweden)

    M. V. Zabolotskyj

    2014-12-01

    Full Text Available We get an approximation theorem for the logarithmic derivative $F$ of entire functions of order zero and, with it's help, establish the asymptotic of $ F $ outside the exceptional set.

  18. T helper type 1 memory cells disseminate postoperative ileus over the entire intestinal tract

    NARCIS (Netherlands)

    Engel, Daniel R.; Koscielny, Arne; Wehner, Sven; Maurer, Juliane; Schiwon, Marzena; Franken, Lars; Schumak, Beatrix; Limmer, Andreas; Sparwasser, Tim; Hirner, Andreas; Knolle, Percy A.; Kalff, Jörg C.; Kurts, Christian

    2010-01-01

    Localized abdominal surgery can lead to disruption of motility in the entire gastrointestinal tract (postoperative ileus). Intestinal macrophages produce mediators that paralyze myocytes, but it is unclear how the macrophages are activated, especially those in unmanipulated intestinal areas. Here we

  19. Quality Characteristics and Composition of the Muscle from Entire and Castrate Elk in Korea

    Directory of Open Access Journals (Sweden)

    Sang-Woo Kim

    2016-05-01

    Full Text Available The objective of the research was to determine the chemical composition as well as the physicochemical properties of the longissimus muscle from Korean entire and castrate elk. Twelve elk stags were raised and fed on concentrate with ad libitum hay. All animals were equally divided into castrated and non-castrated (entire males, and slaughtered at 5 year of age. It was found that entire elk, in comparison with castrate elk, had higher content of moisture and lower content of fat (p<0.05. Compared with entire males, the castrates had lower pH and shear force values (p<0.05. However, castrates had higher L*, a*, and b* values compared with entires (p<0.05. An analysis of the fatty acid profile revealed that the muscles of entire and castrate elk had the most abundant concentrations of the following fatty acids: palmitic acid (C16:0 of the saturated fatty acid, and oleic acid (C18:1n-9 of the unsaturated fatty acid. The entire elk contains higher proportions of linoleic acid (C18:3n6, eicosenoic acid (C20:1n9, and arachidonic acid (C20:4n6 (p<0.05. Cholesterol content in elk was not affected by castration. The predominant free amino acid was glutamic acid related to umami taste. It is apparent that the castrate animals carried higher content of histidine, isoleucine, and leucine than those of the entire group (p<0.05. In this study, it was concluded that venison quality of elk is affected by castration and these results can provide fundamental information for venison production.

  20. Assessing treatment integrity in cognitive-behavioral therapy: comparing session segments with entire sessions.

    Science.gov (United States)

    Weck, Florian; Grikscheit, Florian; Höfling, Volkmar; Stangier, Ulrich

    2014-07-01

    The evaluation of treatment integrity (therapist adherence and competence) is a necessary condition to ensure the internal and external validity of psychotherapy research. However, the evaluation process is associated with high costs, because therapy sessions must be rated by experienced clinicians. It is debatable whether rating session segments is an adequate alternative to rating entire sessions. Four judges evaluated treatment integrity (i.e., therapist adherence and competence) in 84 randomly selected videotapes of cognitive-behavioral therapy for major depressive disorder, social anxiety disorder, and hypochondriasis (from three different treatment outcome studies). In each case, two judges provided ratings based on entire therapy sessions and two on session segments only (i.e., the middle third of the entire sessions). Interrater reliability of adherence and competence evaluations proved satisfactory for ratings based on segments and the level of reliability did not differ from ratings based on entire sessions. Ratings of treatment integrity that were based on entire sessions and session segments were strongly correlated (r=.62 for adherence and r=.73 for competence). The relationship between treatment integrity and outcome was comparable for ratings based on session segments and those based on entire sessions. However, significant relationships between therapist competence and therapy outcome were only found in the treatment of social anxiety disorder. Ratings based on segments proved to be adequate for the evaluation of treatment integrity. The findings demonstrate that session segments are an adequate and cost-effective alternative to entire sessions for the evaluation of therapist adherence and competence. Copyright © 2014. Published by Elsevier Ltd.